They probably want you to define the aqueous throughput and the uptake of the lettuce. The material balance will reduce to an open system, with accumulation (i.e. the lettuce), without chemical reaction or heat transfer. You would need to know the watering requirements of lettuce, the optimal spacing of lettuce and the minimum throughput of water required to prevent stagnation. Design the flow rate for the maximum uptake of properly spaced lettuce, and ensure the water is circulated enough to prevent stagnation. Then, design a collection/piping system. Verify your design using Bernoulli’s, or Hazen-Williams provided there are many nodes in the pipe system. Resolve any issues. That’s all there is to it.This seems more like a weekend homework problem than a senior project. In contrast, my senior project was a to design an entire ethylene plant, including a rigorous furnace design (radiant, conductive, and reactive heat balances, mass balances and momentum balances), quench tower sizing, compressor sizing and acid gas removal, column sizing and internals, refrigeration loops, pinch point analysis of heat exchangers, and an initial estimate of total plant costs. I had to define, size and specify the vessels and internals; the splits and recycles, the furnace tubing, pipes and burners; compressor staging and acid removal system, pump and valve sizing, cooling towers, power requirements, a layers of protection (LOPA) safety analysis, hydraulic sizing of all key flows, capital costs and proposed funding. I would like to know more about how this project panned out. Hopefully, the project provided you an interest in gardening, which like home brewing, catalyst manufacture or cheesemaking, is an empirical science. Let me know how it went. Calico Marty, P.E.

It gave me a chuckle, Janis. I've been messing with computers since 1966 when I took my first course in it, on the big mainframes at our local University. Took a couple more courses in programming down the road in the early seventies. I remember when everyone was WAITING FOR WANG! The vision for PCs was there much earlier than today's kids could imagine. I laughed at Lilo's Luddite comments. I am pretty darned close to one, but I don't cut my nose off to spite my face. I'm fine with technology if it fulfills a purpose for me and then I don't have any problems wrapping my mind around it. I have some really deep seated personal agendas when it comes to the disposable mindset, however. It really rubs me the wrong way to have perfectly good machines sent to the boneyards because the technology behind them has gone defunct. I guess because sometimes that technology doesn't necessarily do a job better. Before Skype, I used to use ICQ. I knew how to use TDY terminals to keep in touch with my deaf friends. I had a cable way back in 1970 twenty years before they became available here, and as soon as digital phones came down the block, I had one. I sat here counting the number of computers I've had over the last twenty years, and I think I am up to six PCs, my first one custom-built before they became available in box stores. However, I just bought my first laptop and had to ask my kids how to turn the danged thing off. LOL. I do know older people who refuse to learn anything electronic. It can bite them in the butt, it can. But, so much of the new stuff coming down the block are toys and expensive ones at that. Fine, if you have the time and money to play. My DD and I have speculated about whether my father would have gotten into computers had he lived past his 81st birthday. We both concluded that he'd have the best systems out there and have them figured out forward and backward.

I use the traditional sredded paper,cardboard and leaves in a thick layer but I sometimes add small quanities of left over castings to incomplete compost after hearvesting worms and useing most of the castings in potting mix. As you would expect, many baby worms and eggs are still in the casings and start a new population in the compost. No top layer is used,just worms cruising around 40 to 50 gallons of cold compost. What I have found is; A. The worms do very well if the compost is kept slightly moist,not enough moisture to hold material in a ball when squeezed. B. No additional feed required. There is plenty in the compost for worms to eat . C. Fewer strange critters inhabit the material at this stage. D. The combination of cold composting and worms yields a better product in less time than if compost is left to finish at it's own pace. E. Material is more friable than normal worm bin making it easy to move around and hearvest a few worms as you might want for fish bait. F. Worms overwinter and rarely require supplimental heat. (I am in N. Cntrl Tx with mild winters) I partily credit this to 7 cu ft of material buffering tempature swings. G. Far less attention and labor is required at the expense of slightly reduced rate of worm reproduction that is more than offset by the quanity of material. If it is true that fishermen are lazy,this might be a good plan for raising worms. You also have castings for swmbo to convince her the intire operation is a labor of love so she can have nice flowers.

Problem is people don't want news. They want Duggars, Kardashians, Orca Windbag, The Spew, Ellen Degenerate, Judge Floozie and other similarly "reputable" sources for getting their "news". Cable seriously wounded both newspapers and local news stations. People want things NOW, not two hours from now. They want to turn on faux news channel and watch someone irrationally bellow about some ridiculous thing and be able to see the high-speed chase du-jour. Makes people feel good because it only happens "there" never "here". Then in sort of a poetic justice, satellite made a dent in cable, so they had to go off into other things like telephone and internet. I used to get a newspaper from up north and one from the central part of the state but when it takes the postal orifice upwards of 2+ weeks to get the paper to you, it's of little use or interest so I quit wasting the money. Plus, now I can use the internet for most of the reasons I wanted to get the papers. It's not just the newspapers that are suffering from it. Local news stations have been hit hard by the internet. Gone are the days of serious in-depth investigative teams. Maybe some will dedicate a part-time reporter or two as their "I-team". No sending reporters to cover big events outstate. Why? Use an affiliate's reporter via satellite. Even the days of a reporter, photographer/cameraman and tech are long gone. Now it's a multi-media journalist who had better be able to operate the editing gear his/herself when they get back. TV stations operate on skeletal news staffs now. Even the days of highly paid anchors are dwindling in most markets. I remember when the local television stations became weather conscious. The ones who could afford it bought their own SupercalifragilisticexpialaMegaDoppler radar systems. The main local stations here had between 12 and 17 on staff meteorologists covering weather 24 hours a day. Now there's 3 per station. And a lot more duties than before too. Apparently the weather has improved since installing Pinpoint WeatherShield SuperStormStalker Radar. And no bad weather at night or on weekends. It's a changing world.