• Title/Summary/Keyword: Maintenance Energy

Search Result 1,399, Processing Time 0.028 seconds

Economic Feasibility Study for Commercial Production of Bio-hydrogen (해양바이오수소개발 사업의 상업생산을 위한 예비경제성평가)

  • Park, Se-Hun;Yoo, Young-Don;Kang, Sung Gyun
    • Ocean and Polar Research
    • /
    • v.38 no.3
    • /
    • pp.225-234
    • /
    • 2016
  • This project sought to conduct an economic feasibility study regarding the commercial production of bio-hydrogen by the marine hyperthermophilic archaeon, Thermococcus onnurineus NA1 using carbon monoxide-containing industrial off-gas. We carried out the economic evaluation of the bio-hydrogen production process using the raw material of steel mill by-product gas. The process parameter was as follows: $H_2$ production rate was 5.6 L/L/h; the conversion of carbon monoxide was 60.7%. This project established an evaluation criterion for about 10,000 tonne/year. Inflation factors were considered as 3%. The operating costs were recalculated based on prices in 2014. The total investment required for development was covered 30% by capital and 70% by a loan. The operation cost for the 0.5-year test and integration, and the cost for the first three months in the 50% production period were considered as the working capital in the cost estimation. The costs required for the rental of office space, facilities, and other related costs from the construction through to full-scale production periods were considered as continuing expenses. Materials, energy, waste disposal and other charges were considered as the operating cost of the development system. Depreciation, tax, maintenance and repair, insurance, labor, interest rate charges, general and administrative costs, lubrication and miscellaneous expenses were also calculated. The hydrogen price was set at US$ 4.15/kg for the economic evaluation. As a result, the process was considered to be economical with the payback period of 6.3 years, NPV of 18 billion Won and IRR of 26.7%.

A Study on The Effect of Dampening Conductivity in the Offset Printing Printability (오프셋인쇄 축임물의 전도도가 인쇄적성에 미치는 영향에 관한 연구)

  • Park, Chan-Woo;Lee, Jae-Soo
    • Journal of the Korean Graphic Arts Communication Society
    • /
    • v.25 no.1
    • /
    • pp.43-52
    • /
    • 2007
  • Offset printing is one of the well known printing technique of lithographic process and consists of image area and 'non-image area on a flat image carrier. The surface tension of dampening water can be controlled by adding IPA after mixing of raw water and etching solution. The etching solution contains a surfactant for reducing surface energy, a clean agent for non-imaging area, wetting agent for protecting non-imaging area from oil components like ink and also an emulsifying agent for controlling emulsification. In this study, the present situation of dampening water maintenance has examined by collecting dampening water using at domestic companies. The pH related to dampening water, conductivity, contact angle, emulsification curve are measured to define the current situation of dampening water control of each companies and to analyze the relationship among measured properties. In the study most of companies among 16 printing companies tested controlling dampening water through pH value. However, the quality of printing has varied depending upon conductivity, contact angle, IPA content, and emulsification value. The control of dampening water should be carry at the state of the standard when adding proper ratio of etching solution. It would be more effective when pH or conductivity control carries out in parallel with controlling dampening water. Therefore the concept that pH5.5 is correct is based concept. Based on these initial tests it is defined that the standardization of dampening water control is required.

  • PDF

A GPS-less Framework for Localization and Coverage Maintenance in Wireless Sensor Networks

  • Mahjri, Imen;Dhraief, Amine;Belghith, Abdelfettah;Drira, Khalil;Mathkour, Hassan
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.10 no.1
    • /
    • pp.96-116
    • /
    • 2016
  • Sensing coverage is a fundamental issue for Wireless Sensor Networks (WSNs). Several coverage configuration protocols have been developed; most of them presume the availability of precise knowledge about each node location via GPS receivers. However, equipping each sensor node with a GPS is very expensive in terms of both energy and cost. On the other hand, several GPS-less localization algorithms that aim at obtaining nodes locations with a low cost have been proposed. Although their deep correlation, sensing coverage and localization have long been treated separately. In this paper, we analyze, design and evaluate a novel integrated framework providing both localization and coverage guarantees for WSNs. We integrate the well-known Coverage Configuration Protocol CCP with an improved version of the localization algorithm AT-Dist. We enhanced the original specification of AT-Dist in order to guarantee the necessary localization accuracy required by CCP. In our proposed framework, a few number of nodes are assumed to know their exact positions and dynamically vary their transmission ranges. The remaining sensors positions are derived, as accurately as possible, using this little initial location information. All nodes positions (exact and derived) are then used as an input for the coverage module. Extensive simulation results show that, even with a very low anchor density, our proposal reaches the same performance and efficiency as the ideal CCP based on complete and precise knowledge of sensors coordinates.

Operational and Performance parameters of Anaerobic Digestion of Municipal Solid Waste (도시쓰레기 혐기성소화 운용 및 성능 지표)

  • Chung, Jae-Chun;Park, Chan-Hyuk;Son, Sung-Myung
    • Journal of the Korea Organic Resources Recycling Association
    • /
    • v.10 no.4
    • /
    • pp.86-95
    • /
    • 2002
  • Anaerobic digestion of municipal solid waste(MSW) is recently getting attention due to energy generation and abatement of global warming. MSW has high solid content and low nitrogen content. Its major component is cellulose and hemicellulose. The conversion rate of organic portion of MSW to methane is approximately 50%, representing $0.2m^3/kg$ VS. Long hydraulic retention time is required for high solid content and inoculum should be mixed with the feed. When MSW is digested anaerobically, maximum limit of C/N ratio is 25 and the optimum concentration of $NH_3-N$ is 700mg/L. lime and sodium bicarbonate are used to adjust pH. Excess addition of sodium bicarbonate above 3,500mg/L will cause sodium toxicity. Thermophilic anaerobic digestion is effective in the control of pathogen although its operation and maintenance is difficult. To optimize the anaerobic digestion of MSW, it is necessary to understand the mechanism of microorganims involved in anaerobic digestion.

  • PDF

Effect of Restricted and Ad libitum Feeding of Urea Molasses Liquid Diet (UMLD) on the Performance of Adult Crossbred Cattle

  • Mehra, U.R.;Verma, A.K.;Dass, R.S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.11 no.1
    • /
    • pp.30-34
    • /
    • 1998
  • To compare response of feeding concentrate mixtere and wheat straw (Group I) with either urea molasses liquid diet (UMLD) as sole ration (group II) or UMLD (similar to protein equivalent of concentrate mixture) plus wheat straw (group III) on intake and utilisation of nutrients and overall performance, twelve crossbred adult male cattle (Holstein Friesian ${\times}$ Hariana) aged about 2.5 years and weighing 342 kg were randomly allotted into three equal groups following completely randomised design and fed respective diets for a period of 60 days. Thereafter, a metabolism trial of seven days duration was conducted to assess nutrient utilisation and nitrogen balance. Animals fed UMLD as sole ration consumed significantly (p < 0.01) less amount of most of the nutrients as compared to other two groups, except crude protein, intake of which was higher in this group but it was comparable between II and III and III and I. On the other hand, digestibilities of nutrients were higher (p < 0.01) in group II, though it was comparable between other two groups, except ADF, the digestibility of which was lower in group II. Inspite of positive nitrogen balance in all the three groups, being significantly (p < 0.01) higher in group I, animals of group II and III lost their body weight especially to the utmost extent in group II, although the amount of energy (TDN) intake were similar statistically. Results indicate that during a scarcity period and economic compulsions, feeding of UMLD can be practised to replace only concentrate mixture from the maintenance ration of adult crossbred cattle for shorter duration as roughage part seems to be essential for the normal functioning of the rumen microbes and overall performance of the animals.

Analyses on the Factors Related to Stages of Dietary Behavioral Changes among Child Bearing Aged Women (가임여성에서 식행동 변화단계에 따른 식생활 요인 분석)

  • 권성옥;오세영
    • Journal of Nutrition and Health
    • /
    • v.36 no.7
    • /
    • pp.759-768
    • /
    • 2003
  • This study examined the factors related to stages of dietary behavioral changes among 1449 child bearing aged women (mean age $\pm$ SD = 25.6 $\pm$ 5.3 years) residing in large cities. A self administered questionnaire was used to assess stages of dietary behavioral change, meal balance and regularity, food availability, nutrition knowledge, body mass index, nutrient intake, and psycho-social factors including self efficacy, perceived benefits and barriers, social modeling. Undesirable dietary behaviors (precontemplation and contemplation) were shown among 45.1-57.4% of the participants, among those, 33.4-43.0% were precontemplators. Participants' self efficacy scores associated with dietary changes were higher in specific situations (3.42) as compared to general situations (2.86). Similarly, they appeared to perceive more benefits (3.86) rather than barriers (2.76) by changing their inappropriate eating habits. Perception and accuracy scores of nutrition knowledge were relatively high, indicating 90.9 and 80.1, respectively. In terms of food availability at home, fresh fruits received the highest score, followed by milk and milk products, vegetables, meat, alcoholic beverages and soft drinks. In social modeling assessment, family members, as compared to friends, appeared to have better dietary habits. Stages of dietary behavioral change assessed in terms of meal regularity were associated with nutrient intake, showing higher energy and carbohydrate intakes but lower fat intake among those who belonged to the action and maintenance stage. They also presented higher self efficacy and perceived more benefits and less barriers regarding the change of undesirable eating habits. Fresh meat and vegetables were more available among those maintaining desirable dietary habits. Results of this study presented the significant relations of motivational and reinforcing social factors with stages of dietary behavioral changes and a need for the development of tailored nutrition education program considering these factors for child-bearing aged Korean women.

An innovative BRB with viscoelastic layers: performance evaluation and numerical simulation

  • Zhou, Ying;Gong, Shunming;Hu, Qing;Wu, Rili
    • Structural Monitoring and Maintenance
    • /
    • v.5 no.2
    • /
    • pp.205-229
    • /
    • 2018
  • Energy induced by minor earthquake and micro vibration cannot be dissipated by traditional buckling-restrained braces (BRBs). To solve this problem, a new type of hybrid passive control device, named as VE-BRB, which is configured by a BRB with high-damping viscoelastic (VE) layers, is developed and studied. Theoretical analysis, performance tests, numerical simulation and case analysis are conducted to study the seismic behavior of VE-BRBs. The results indicate that the combination of hysteretic and damping devices lead to a multi-phased nature and good performance. VE-BRB's working state can be divided into three phases: before yielding of the steel core, VE layers provide sufficient damping ratio to mitigate minor vibrations; after yielding of the steel core, the steel's hysteretic deformations provide supplemental dissipative capacity for structures; after rupture of the steel core, VE layers are still able to work normally and provide multiple security assurance for structures. The simulation results agreed well with the experimental results, validating the finite element analysis method, constitutive models and the identified parameters. The comparison of the time history analysis on a 6-story frame with VE-BRBs and BRBs verified the advantages of VE-BRB for seismic protection of structures compared with traditional BRB. In general, VE-BRB had the potential to provide better control effect on structural displacement and shear in all stages than BRB as expected.

Evaluation of Fishmeal Supplement with Net Nitrogen Flux by the Portal-drained Viscera and the Liver in Mature Sheep

  • Fukuma, T.;Taniguchi, K.;Obitsu, T.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.18 no.9
    • /
    • pp.1255-1261
    • /
    • 2005
  • The objective of this study was to evaluate the net flux response of nitrogen compounds (alpha-amino N, ammonia N, urea N, essential amino acids) across the portal-drained viscera (PDV), liver and total splanchnic tissues of mature wethers to increasing level of dietary fishmeal (FM) supplementation. Four wethers (average body weight, 64 kg) with chronic indwelling catheters into the portal, hepatic and mesenteric veins and the abdominal aorta were used in a 4${\times}$4 Latin square design. A basal diet consisting of 0.7 hay and 0.3 concentrate was fed twice daily with a fixed amount at 1.4 times maintenance energy (1.3 kg/day on a dry matter basis). The supplementation proportion of FM as treatment was 0, 0.03, 0.06 and 0.09 to the amount of the basal diet to contain 119, 137, 154 and 170 g crude protein per kg dietary dry matter, respectively. Blood flows through PDV and liver did not differ (p>0.05) among the treatments. Both net PDV release and hepatic uptake of alpha amino acid N increased linearly (p<0.05) in response to increased dietary FM, which resulted in similar total splanchnic release of alpha-amino N among the treatments. Similarly, increased dietary FM increased net PDV absorption and hepatic removal of ammonia N linearly (p<0.05). Hepatic synthesis and total splanchnic release of urea N increased linearly (p<0.01) with increased dietary FM, but PDV uptake of urea N did not respond to increased dietary FM. Linear regression equations between the increases in FM N intake and PDV net flux indicated that 0.34 and 0.30 of FM N was absorbed in the form of alpha-amino N and ammonia N, respectively. The results demonstrated that FM supplementation provides more alpha-amino N than ammonia N to the liver, but the alpha-amino acid N absorption is less than the expected metabolizable protein N from FM supplementation.

Effect of Rumen Degradable Protein (RDP) in Straw Based Ration on Purine Derivatives Excretion and Microbial Nitrogen Supply in Cattle

  • Khandaker, Z.H.;Tareque, A.M.M.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.10 no.4
    • /
    • pp.364-370
    • /
    • 1997
  • Four local cattle were ($145{\pm}9.7kg$) used in a $4{\times}4$ Latin square design to study the effect of different levels of rumen degradable protein (RDP) in straw based ration on purine derivatives excretion and microbial N supply in cattle. The four rations were formulated at the same amount of energy but varying RDP approximately 50 (U0), 75 (U1), 100 (U2) and 150 (U3) percent levels of RDP requirement for maintenance. They were fed ranged from 101 to 304 g RDP/d. Apparent digestibility of all nutrients increased significantly (p < 0.01) in cattle fed ration U2 than other rations. Rumen $NH_3-N$ concentration increased from 43 to 130 mg/l in response of RDP intake. Purine derivatives excretion increased significantly (p < 0.01) with incremental level of 203 g RDP/d (U2) intake and positively correlated (r=0.69, p < 0.01, n=16) with amount of RDP intake. The rates of rumen microbial N supply were 16.8, 27.2, 39.1 and 32.9 g/d for rations U0, U1, U2 and U3 respectively. Efficiency of microbial N supply (EMNS) per kg of DOMR were 19.0, 25.3, 33.0, and 28.6 g and per MJ of ME. Intake were 0.62, 1.00, 1.44 and 1.21 g for U0, U1, U2 and U3 respectively and highest results were obtained in cattle fed U2 ration. Results of this study suggest that PD excretion and EMNS were increased as incremental level of RDP intake (U2) in local cattle.

Effects of Plantain (Plantago lanceolata L.) Herb and Heat Exposure on Plasma Glucose Metabolism in Sheep

  • Al-Mamun, M.;Tanaka, C.;Hanai, Y.;Tamura, Y.;Sano, H.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.20 no.6
    • /
    • pp.894-899
    • /
    • 2007
  • An experiment was conducted using a [6, 6-$^2H$]glucose isotope dilution method to determine the effects of plantain (Plantago lanceolata L.) on plasma glucose metabolism in sheep taken from a thermoneutral environment and exposed to a hot environment. The sheep were fed either mixed hay (MH) of orchardgrass (Dactylis glomerata L.) and reed canarygrass (Phalaris arundinacea L.) at a 60:40 ratio or MH and plantain (PL) at a 9:1 ratio in a crossover design for each 23-day period. In both dietary treatments the metabolizable energy (ME) and crude protein intake were designed to be isoenergetic and isoproteinous at around maintenance level. The sheep were taken from a thermoneutral environment ($20^{\circ}C$, 70% RH) and exposed to a hot environment ($28-30^{\circ}C$, 70% RH) for 5 days. The isotope dilution method using a single injection of [6, 6-$^2H$]glucose was performed on the $18^{th}$ day of the thermoneutral environment and on the $5^{th}$ day of heat exposure. Plasma glucose pool size was numerically lower (p = 0.26) during heat exposure on both dietary treatments, and numerically higher (p = 0.13) on the MH diet irrespective of environmental temperature. Plasma NEFA concentration (p = 0.01) and glucose turnover rate (p = 0.03) were decreased during heat exposure, but remained similar between diets. It could be concluded that, although no positive impact of plantain on glucose metabolism was found under the present experimental conditions (plantain constituted only 10% of basal diet), plantain herb is an alternative to MH for rearing sheep in both thermoneutral and hot environments.