Bio Computer

Mike SchroppComputers 40620 Comments

With every passing project I feel like my basement is being converted from a living only area, to a work and project area. Computers being built, gadgets being taken apart, Lego projects all around. I’m not complaining by any means, but I do feel as my basement becomes populated with more and more tech based projects that the environment is missing something organic, something natural to balance things out.

Biological Computer

Bio Computer

I’ve been interested in working on a project for while that would combine something tech-based with something organic. Mixing the two elements intrigued me for a while. I’ve wanted to add flowers, or maybe plants of some sort to blend a little bit of nature into the space. I do receive a bit of sunlight through a glass block window, but the temperature in the basement is usually on the colder side. In the winter I don’t really heat the space because the folding farm outputs enough heat to keep the temperature comfortable. I didn’t want to change that aspect so I needed to come up with something that would tolerate slightly cooler temperatures and limited sunlight.

I can’t exactly recall when the idea came to me, but at some point I started wanting to use the heat from a computer as a way to warm the soil and help with germination/growth. I’m about as far from a botanist as it comes, I did some reading online and became pretty interested in the effects of soil temperature on germination/growth. I read different studies and papers from various universities. It was not too long into that process that I became hooked on the idea of using computer heat as a way to control the soil temperature of some sort of living plant life.

As the idea developed further I started looking into wheatgrass as a plant option. There is something clean and natural about the look and idea of a piece of grass growing in my basement. I thought the look would alter the space a little bit and add a bit of color along with something more than just metals and plastics. After reading enough studies and papers on the effects of soil temperature and germination with wheatgrass I felt like I had a good enough handle on the basics to tackle this.

The first step was finding a computer to adapt for the project. Luckily I had a lot of donated computers that people had given me for various project purposes. Most of them didn’t work, but by cobbling together various components from a bunch of different old computers I was able to come up with enough good parts to make a working computer.

Salvage Computer

Donor Computer

At the time I was starting to get a formalized plan together for this project, another idea popped into my head. I’ve got a 5 yr. old who is already fairly geeky (just ask him to do his Jabba the Hutt impression for you) but he really does not get that much computer time. He’s getting to an age where he’s more inquisitive about tech stuff and I think he’s ready for his first computer. Since I was already well underway with this project it seemed like a perfect opportunity to orient the computer itself towards a learning tool for him in addition to using it as a way to blend something organic with a piece of technology.

With all of these goals in mind I started tinkering away. The computer hardware itself was nothing fancy, definitely outdated, but perfectly suited towards this project.

CPU- Pentium 4  (3 GHz)
Dell Factory Motherboard
Various Ram Sticks- 2gb
Old Maxtor 120gb IDE Hard Drive
Old FPS Power Supply
Donated Old Computer Case

Computer Component Testing

Computer Parts Testing

 

If you’ve spent any time around computer hardware in the last decade you’re probably well aware that Pentium 4 has a reputation for running hot. The 90nm Pentium 4 was named Prescott and it didn’t take long before the nickname Pres-hot popped up. In this case though that extra heat is going to be put towards good use.

Once the hardware was all in order I started working on the layout and arrangement for the case. I had originally envisioned the grass growing out of the top of the computer case. This seemed like it would provide a good blend between the hard edges of the computer and the soft feel of the grass. This also worked well with putting the soil area in the upper portion of the case, where the most heat should collect. After doing some initial tests with this configuration I found the measured temperature near the top of the case was the hottest. The placement of the CPU near the top of the case and the lack of airflow in that area contributed to these higher recorded temps.

After finishing with some initial tests I decided to completely strip the case down and start removing all the unnecessary brackets and pieces inside of the case. Like most computer cases all the internal brackets and mounts are riveted together, so I drilled all the rivets out of the components I wanted to remove and pulled them out. The gutted case looked pretty barren after being stripped.

Stripped Computer Case

Empty Computer Case

Computer Case Stripped

Dismantled Computer Case

Dismantled Computer Case

Stripped Computer Case

In keeping with my original plan of having the computer blended with the organic grass I wanted it to be easy to see the inner workings of the computer and also the soil from the grass growing above. I needed something that was translucent, which left me with either glass or acrylic/polycarbonate as my options. I ended up choosing acrylic because I was able to find a cheap, used, die-cast model car display case top that was the perfect dimensions for the top of the case. Couldn’t go wrong for 5 bucks.

I test-fit the acrylic over the top of the computer case and marked my layout on the top of the case. My plan was to cut open the top of the computer case and insert the acrylic display case into the section I cut out. To cut open the top of the computer case I drilled a hole as a starting point and then used tin snips to cut through the thin gauge metal.

Computer Case Top

Computer Case Lid Modding

Once I had the metal opening cutout, I needed something to put along the edges of the freshly cut opening to create a clean and finished look. For $2 I was able to find some black, car-door-edge, plastic molding that worked perfectly.

Computer Case Top

Modified Computer Case Lid

After getting the opening of the top of the computer handled and the acrylic case properly fitted, I moved onto some more testing with soil in the acrylic and the computer running. I wanted to see what kind of heat transfer I would get and how it would affect the soil temperature. I knew that using acrylic over glass would make it a little more difficult to heat the soil as acrylic is not that good at transferring heat. Luckily though I didn’t really need to alter the soil temperature that much, I just needed a little extra heat. Testing showed that heat transfer with just the single acrylic display case as my soil container was slow. So I decided to add some acrylic tubes. This would allow more surface are for soil to acrylic contact and also give me an area where I could add a mixed substrate to allow for soil drainage.

I went online and found a 3ft long section of 2 1/4″ clear acrylic tubing for $8 dollars. I wanted to add a couple of hanging cylinders off the main of the acrylic display case in the top of the computer case. To do this I needed to cut holes into the bottom of the display case. Cutting holes in acrylic is not always easy, it’s likely to chip and craze at the edges. To get around this I used a buildup of masking tape on both sides of the acrylic, to provide a little bit of resistance and strength. I placed the acrylic display case back into the computer and marked my layout for the tubes. I needed to leave clearance for the CPU cooler, power supply and hard drive mount.

After marking the layout, I used an air-powered pencil grinder and carbide tipped bit and cut through the acrylic case along my marked lines. After the initial shape was cutout I used a tube piece as a template and slowly worked on grinding the holes as perfectly round as I could get them so that the tube had a snug fit all the way around. The fit is pretty important as the acrylic cement that I used needs there to be a tight fit so that the acrylic can bond correctly.

Modified Acrylic Case

Acrylic Case Modifications

I placed the tubes into the acrylic case and mounted it in the computer and test fit the placement and height of the tubes. After getting everything lined up and oriented correctly I moved towards bonding the acrylic together. Using a needle dropper applicator I applied the cement to all the joints. After letting it set overnight I came back the next night and applied a thin coating of clear silicone caulk around all the joints just to ensure they were completely water tight

Acrylic Tube Sections

Acrylic Tubes

The next step was sealing up the bottom of the acrylic tubes. I looked at a couple of different options before realizing that the discs I had cut out of the acrylic case to fit the tubes would be almost the perfect size. Using a bench grinder and a test piece of tube I slowly ground each disc to the perfect size for a tight fit all the way around. I placed the clear acrylic discs into the bottom of each tube and repeated the same cementing and silicone caulking procedure to ensure they were water-tight. After a couple of days’ worth of drying I tested the case by filling it with water overnight and checking in the morning to make sure that no leaks had popped up.

In order to hold the weight of the acrylic case after adding soil, I drilled and installed a machine screw with a rubber cap at each corner of the computer case to bear the weight of the acrylic case.

Once all the work was done with the acrylic case section I started reinstalling all the components. The motherboard, hard drive and power supply were added and then wired up.

Computer Case Mock Up

Mocked Up Computer Case

Wiring Mockup

Power Supply Mockup

Power Supply Wiring

Computer Components Wired

Computer Side Panel Installed

Case Panel Installed

At this point all that was left was to make a clear panel for the side of the case. I had some left over acrylic sheets from a different project that were really close to the right size, after test fitting, marking and cutting I then had a clear side panel to see into the case. (I left this off for the pictures because it caused a reflection)

The final step was filling the case with soil and adding some wheatgrass. I had been test growing other samples of wheatgrass during the build process. So I had already a couple of different patches of grass growing. I tried to keep the soil level just below the top of the acrylic case edge to make it a little more seamless.

Computer Case Grass

Grass Planted in Computer

Grass Computer Panel

Grass and Case Panel Installed

Computer Grass Complete

Grass in Computer

For the computer itself I ended up installing Windows as well as Linux in a dual boot setup. Since the computer was going to be used by my son as something to play with I figured I should put both on there so he can tinker with them and learn as he goes. Besides, for important life decisions like picking an OS (Operating System) I think any good parent should present the options and then let their kid decide for themselves.

Windows Starting in Computer

Starting Windows

Linux Running in Computer

Linux Running

Dual Booting Screen

Dual Boot Screen

In the end I’m happy with the result of the project. It’s been fun experimenting with growing wheatgrass and I like how the natural look of grass is blended with the very modern, inorganic case.

Growing Grass in Computer

Computer Grass Growing

Grass Growing in Computer

Grass in Computer Section

  

Notes

Temperature Testing

In testing the case temperature versus the soil temperature I found it was easiest to control the case temperature by using a variable fan speed control on both the inlet and outlet fans. By turning the fan speed down I could increase the temperature inside the case and correspondingly raise the soil temperature.

In order to maximize output of heat during these tests I used Prime95 to run the CPU at 100% load.

Using this method to control the case and soil temperature I played around with adjusting the soil temperature and then tracking the rate of growth of the Wheatgrass. The target temperature for peak growth seemed to fall around 66°F (19°C).

Using the fans to control the case temperature allowed me to vary the temperature inside the case from a low of 75°F (24°C) to a high of 91°F (33°C). In order to achieve the desired increase in soil temperature, I had to run the case temperature toward the higher end of the scale.

When the soil temperature was too high, the growth of the wheatgrass would slow.

 

Wheatgrass

The wheatgrass I used for my tests was nothing special, it can be found as seeds (berries) in a lot of health food stores and it grows relatively easily.

Caring for the wheatgrass is just a matter of keeping it watered. It’s a pretty easy plant to work with and doesn’t require any special skills.

Wheatgrass is often used as a nutritional supplement; it can be juiced and mixed into smoothies and other beverages. I plan on harvesting some of the grass and making some juices.

 

Plant Options

While wheatgrass offers a nice, attractive and easily grown option I do plan on trying other plants as well in the future. Since I already have the “planter” built all I have to do is add a different plant and see how it goes. I’m sure there will be some plants that don’t like the lower light environment, but it will be fun experimenting with other plants as well and seeing how they take.

 

Materials

Donated Computer- Free
Clear Acrylic Display Case- $5
Clear Acrylic Tube- $5
Plexiglass Side Panel- Free

Total- $10

Working Computer with Grass

Bio Computer Running

 

Facebook29.2k
Twitter13.2k
Pinterest7.1k
Pinterest
Pinterest
LinkedIn2.1k
RSS813
Follow by Email2.6k

Comments 40,620

  4. Сейчас по России что то не видно вас.Только пожелать ветра в парус,адекватных клиентов по меньше шкур
    https://rant.li/qecyoygeh/kupit-zakladku-s-narkotikami-spb
    Порошок серого цвета чем то похож на известь, запаха нет, ну или очень слабый. Фото сделать не вышло сори :dontknown:!

    Reply

  6. Гибкое остекление Гибкие окна для беседок: прекрасная возможность создать уютное и защищенное место для отдыха на свежем воздухе. Легко устанавливаются и снимаются, позволяя адаптироваться к любым погодным условиям. Превратите свою беседку в оазис комфорта.

    Reply

  15. у меня такое было, позвонил в офис доставки так они меня там ошарашили что груз ушел но совсем в другую сторону от меня, я в шок че за на.. через 2часа звонок вам пакет, я аж от радости чуть не описался :voo-hoo: тут все на уровне. Не паникуйте раньше времени все решаемо. Всем добРА
    https://bio.site/hkzuhicicmyc
    как дела народ ? Всё хорошо ? не у кого проблем нет ?

    Reply

  16. Хотите купить, где оперативно получить официальную справку в Санкт-Петербурге без толпы и лишних проблем? На [url=https://doktor-smajl-med.ru]https://doktor-smajl-med.ru[/url] доступны форма 095/у, форма 027/у, формы из диспансеров, справки на академический отпуск и многое другое — все оформление проходит законно и отправляются курьерской доставкой, в удобное место или работу. Стоимость понятна, доступная стоимость, надёжность обеспечена. Услуга подходит для студентов, работников и семей — минимум хлопот. Подробнее на сайте — справка Петербург, медсправка без ожидания, курьерская доставка справки.

    Reply

  22. Оплатил заказ до нового года, связывался через почту, написали оплата прошла, отправка будет после праздников, … ответа до сих пор нет… Сделайте что нибудь, ответьте мне на почте емае, хз уже чо делать.
    https://900e8099a6664828f0ef2e897e.doorkeeper.jp/
    Бро, доброго дня. В личку реквы на оплату жду, на сайт тоже попасть не могу…

    Reply

  25. Israel’s attack in Doha was not entirely surprising, given Israel’s vow to eliminate Hamas — but some aspects of it are still shocking.
    [url=https://megasbmegadarknetmarketonionhydrashopomgomgrutor555cnyid.com]mega2onq5nskz5ib5cg3a2aqkcprqnm3lojxtik2zeou6au6mno7d4ad.onion[/url]
    Here are three main reasons:
    [url=https://mega555kf7lsmb54yd6etzginolhxxi4ytdoma2rf77ngq5fhcnid.com]mega2oakke6o6mya3lte64b4d3mrq2ohz6waamfmszcfjhayszqhchqd.onion[/url]
    Israel claimed credit immediately – in contrast to the last time the Israelis targeted a Hamas leader outside Gaza.
    The US and Israel had asked Qatar to host Hamas leaders. Hamas’ location was not a secret. There was an unstated understanding that while Israel could assassinate the leaders, they would not do so, given Qatar’s mediation role.
    The strike makes a hostage deal less likely, since any agreement requires negotiating with Hamas leadership in Doha.
    Subscribers can read the full analysis here.
    https://mega555kf7lsmb54yd6etzginolhxxi4ytdoma2rf77ngq55fhfcnyid-onion.com
    mega2o2nde2gzktxse2fesqpyfeoma72qmvk3fkecip2l3uv3tbn5mad.onion

    Reply

  26. Да хватает придурков, только смысл писанины этой , что он думает что ему за это что то дадут ))) кроме бана явно ничего не выгорит )))! Тс красавчик брал 3 раза по кг сделки и всегда все чётко ! Жду пока появиться опт на ск!
    https://www.divephotoguide.com/user/difiyghifog
    НЕТ не пришла, но это у СПСР экспресс вообще какая то лажа, раньше все привозили вовремя, а теперь вообще какую то чепуху сочиняют, звонил говорят не знаем почему посылку курьер не взял…

    Reply

  27. What we’re covering
    [url=https://megaweb20at.com]mgmarket4.at[/url]
    • Israel is facing growing condemnation after it attacked Hamas leadership in the capital of Qatar, a US ally and key mediator in Gaza ceasefire talks — putting hostage negotiations at risk.
    [url=https://megaweb2at.com]mgmarket5 at[/url]
    • Hamas said the strike killed five members but failed to assassinate the negotiating delegation, the target of the strikes.
    • US President Donald Trump has criticized the strike, saying that by the time his administration learned of the attack and told the Qataris, there was little he could do to stop it.

    • The attack is the first publicly acknowledged strike on a Gulf state by Israel. Qatar’s prime minister was visibly angry and said his country’s tradition of diplomacy “won’t be deterred.”
    https://megaweb18at.com
    mgmarket6

    Reply

  35. What we’re covering
    [url=https://megasb24.com]megaweb5.com[/url]
    • Israel is facing growing condemnation after it attacked Hamas leadership in the capital of Qatar, a US ally and key mediator in Gaza ceasefire talks — putting hostage negotiations at risk.
    [url=https://mgmarket7at.net]mgmarket5.at[/url]
    • Hamas said the strike killed five members but failed to assassinate the negotiating delegation, the target of the strikes.
    • US President Donald Trump has criticized the strike, saying that by the time his administration learned of the attack and told the Qataris, there was little he could do to stop it.

    • The attack is the first publicly acknowledged strike on a Gulf state by Israel. Qatar’s prime minister was visibly angry and said his country’s tradition of diplomacy “won’t be deterred.”
    https://megaweb19at.com
    mgmarket 6at

    Reply

  37. What we’re covering
    [url=https://megaweb2at.com]mgmarket5.at[/url]
    • Israel is facing growing condemnation after it attacked Hamas leadership in the capital of Qatar, a US ally and key mediator in Gaza ceasefire talks — putting hostage negotiations at risk.
    [url=https://megaweb-7at.com]mgmarket6 at[/url]
    • Hamas said the strike killed five members but failed to assassinate the negotiating delegation, the target of the strikes.
    • US President Donald Trump has criticized the strike, saying that by the time his administration learned of the attack and told the Qataris, there was little he could do to stop it.

    • The attack is the first publicly acknowledged strike on a Gulf state by Israel. Qatar’s prime minister was visibly angry and said his country’s tradition of diplomacy “won’t be deterred.”
    https://mega-market-dark.net
    mgmarket

    Reply

  38. What we’re covering
    [url=https://megaweb20at.com]mgmarket5[/url]
    • Israel is facing growing condemnation after it attacked Hamas leadership in the capital of Qatar, a US ally and key mediator in Gaza ceasefire talks — putting hostage negotiations at risk.
    [url=https://megaweb19at.com]mgmarket4[/url]
    • Hamas said the strike killed five members but failed to assassinate the negotiating delegation, the target of the strikes.
    • US President Donald Trump has criticized the strike, saying that by the time his administration learned of the attack and told the Qataris, there was little he could do to stop it.

    • The attack is the first publicly acknowledged strike on a Gulf state by Israel. Qatar’s prime minister was visibly angry and said his country’s tradition of diplomacy “won’t be deterred.”
    https://megasb.cc
    megaweb 4

    Reply

  39. Hey folks,

    I’ve been exploring the world of internet gambling lately, and I’ve gotta say — it’s surprisingly fun. At first, I was super skeptical. I mean, how do you even believe in an online platform with your money, right? But after testing the waters (and trying out a few questionable sites so you don’t have to), I figured out a few things that set apart a trustworthy casino from a risky mess. First off, if you’re new to all this, here’s the golden rule: **licenses matter**. If a casino doesn’t have a proper legal status (like from the Malta Gaming Authority or the UKGC), just walk away. No bonus is worth the risk of never seeing your funds again. Also — and I know no one wants to — go through the small print. That’s the only way to know what kind of hidden traps they’ve slapped onto those so-called “juicy” bonuses.

    Now, let me share a site I’ve been playing on these last few weeks. It’s been a game-changer. The interface? Super clean. Payouts? No waiting around. And the game selection? *Massive*. Slots, live dealers, blackjack, even some oddball options I hadn’t tried before. Check it out here: billionaire spin . What really stood out was the help desk. I had a tiny issue with a bonus not working, and they got back to me in like no time. Compare that to other sites where you’re just shouting into the void — yeah, no thanks.

    Also, if you’re into bonuses (and who isn’t?), this place offers some legit ones. But here’s the trick: don’t just grab every shiny offer. It’s smarter to go for reasonable terms than a huge bonus you’ll never be able to withdraw. I’m not saying you should go and bet the farm — please don’t. But if you’ve got a little extra cash and you’re looking for a bit of online excitement, online casinos can totally deliver. Just stay sharp, set a budget, and don’t treat it like a side hustle. It’s for fun, not for a paycheck. Anyway, just wanted to drop my experience here in case anyone’s looking for solid info or trying to find a trustworthy place to play. If you’ve got your own recommendations or even some casino nightmares, I’m all ears — love talking shop about this stuff.

    Good luck out there, and may the odds be ever in your favor ??

    Reply

  40. магазин работает как надо, у меня тут перевес был не плохой спасибо дружбанчики
    https://igli.me/wfivvely0ns
    Хз, смотри, в тёплой кипяченке начали болтать, растворяется. Точно не рега

    Reply

  43. брат, у меня ощущение что я с тобой работал, но название магаза было немного другим, тоже в доверенной ветке был))) почерк тот же, и порядочность. я прав или ошибаюсь?))
    https://www.impactio.com/researcher/fairesmaria9
    все супер! магазину доверять можно, были небольшие задержки но ТС сделал все по красоте!

    Reply

  45. https://start.me/w/v9zARM

    Pasar una prueba de orina puede ser complicado. Por eso, se ha creado una solucion cientifica con respaldo internacional.

    Su formula eficaz combina carbohidratos, lo que sobrecarga tu organismo y neutraliza temporalmente los marcadores de alcaloides. El resultado: una prueba sin riesgos, lista para entregar tranquilidad.

    Lo mas interesante es su ventana de efectividad de 4 a 5 horas. A diferencia de metodos caseros, no promete milagros, sino una herramienta puntual que te respalda en situaciones criticas.

    Miles de postulantes ya han experimentado su efectividad. Testimonios reales mencionan paquetes 100% confidenciales.

    Si no deseas dejar nada al azar, esta alternativa te ofrece tranquilidad.

    Reply

  46. https://start.me/w/v9zARM

    Enfrentar un examen de drogas ya no tiene que ser una pesadilla. Existe una alternativa científica que actúa rápido.

    El secreto está en su mezcla, que sobrecarga el cuerpo con nutrientes esenciales, provocando que la orina neutralice los metabolitos de toxinas. Esto asegura una muestra limpia en menos de lo que imaginas, con efectividad durante 4 a 5 horas.

    Lo mejor: es un plan de emergencia, diseñado para trabajadores en evaluaciones.

    Miles de usuarios confirman su efectividad. Los paquetes llegan sin logos, lo que refuerza la seguridad.

    Si tu meta es asegurar tu futuro laboral, esta alternativa es la respuesta que estabas buscando.

    Reply

  48. Готовы жить ярко, стильно и со вкусом? «Стиль и Вкус» собирает лучшие идеи моды, красоты, ЗОЖ и еды в одном месте, чтобы вдохновлять на перемены каждый день. Тренды сезона, работающие лайфхаки, простые рецепты и привычки, которые действительно делают жизнь лучше. Читайте свежие выпуски и применяйте сразу. Узнайте больше на https://zolotino.ru/ — и начните свой апгрейд уже сегодня. Сохраняйте понравившиеся материалы и делитесь с друзьями!

    Reply

  49. Чувствуете, что подарок должен говорить за вас? Серебряные изделия ручной работы из Кубачи от «Апанде» сохраняют тепло мастера и становятся семейной ценностью. В каждой ложке, чаше или подстаканнике — филигрань, чеканка и орнаменты с историей. Ознакомьтесь с коллекцией на https://www.apande.ru/ и выберите вещь, которая подчеркнет вкус и статус. Поможем подобрать, сделать гравировку и аккуратно доставим заказ. Подарите серебро, которое радует сегодня и будет восхищать через годы.

    Reply

  50. Хотите купить, где оперативно получить медицинскую справку в СПб без очередей и лишних проблем? На [url=https://doktor-smajl-med.ru]https://doktor-smajl-med.ru[/url] можно заказать форма 095/у, 027/у, документы ПНД/НД, академотпуска и др. — все оформление проходит законно и доставляются курьером на дом, в любой район или место работы. Оплата прозрачная, недорогие расценки, надёжность обеспечена. Подходит для учащихся, сотрудников и частных лиц — минимум хлопот. Подробнее на сайте — медсправка СПб, медсправка без ожидания, справка с доставкой.

    Reply

  59. Дружище как все прошло?)) забрал своё??? А то написал неделю назад и тишина))) если забрал сколько шло по времени? напиши нам а то на последних страницах сдесь какой то кипишь нездоровый…(
    https://igli.me/hhnilicalifethree
    Как связаться можно

    Reply

  61. и вот я решил зайти на ветку доверенных магазинов! и почему то решил ткнуть именно на ссылку чемикл микс! захожу дыбанул на ценник, устроило и даже очень! так же порадовало то что тут делают отправку! а это значит то что если товар отправят то ты его 100% получишь! главная особенность магазина в том что отправка делается от 5грамм 🙂 а это значит то что я смогу и опробывать товар и убидится в качестве товара, и в надежности магазина!
    https://www.brownbook.net/business/54246694/гашиш-на-реагенте-купить-в-москве/
    народ подскажите а как дела обстоят в столице Москва закладками?

    Reply

  65. у тебя все пришло? отпиши в лс.
    https://www.divephotoguide.com/user/dugufefebo
    У меня кстати тоже через 2 дня пришло, но в соседний город, так как в моём городе этой конторы не оказалось) но мне сразу позвонили, и предложили либо самому приехать за пакетом, либо подождать до вторника и мне его привезут домой. Вот жду)

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *