MODELING UNCERTAINTY IN QUASI-HYDROSTATIC ISOTHERMAL SELF-GRAVITATING SLAB

Nejad-Asghar, Mohsen The Korean Astronomical Society 2007 Journal of The Korean Astronomical Society Vol.40 No.1

The smoothed particle hydrodynamics (SPH) method is applied to construct the dispersion of fluctuations in quasi-hydrostatic configuration of an isothermal self-gravitating slab. The uncertainty of the implementation is evaluated, and a novel technique (acceleration error) is proposed to weaken this uncertainty. The two-fluid quasi-hydrostatic diffusion of small fluctuations is used to support the importance of the acceleration error. The results show that the uncertainty converges to a few percent by increasing of the SPH particle numbers. Considering the acceleration error weakens the uncertainty, and prohibits the serious dynamical consequences in slow dispersion of fluctuation in the quasi-hydrostatic evolution of the slab.

Effects of water addition to total mixed ration on water intake, nutrient digestibility, wool cortisol and blood indices in Corriedale ewes

Nejad, Jalil Ghassemi,Kim, Byong-Wan,Lee, Bae-Hun,Kim, Ji-Yung,Sung, Kyung-Il Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.10

Objective: The objective of this study was to determine the effect of adding water to total mixed ration (TMR) on fresh water intake, nutrient digestibility, wool cortisol, and blood indices in Corriedale ewes under hot and humid conditions. Methods: Nine non-pregnant Corriedale ewes (ave. body weight = $41{\pm}3.5kg$) were individually fed diets based on maintenance requirements in metabolic crates. Ewes were assigned to three treatment groups according to a triplicate $3{\times}3$ Latin Square design for 3 periods of 21 days duration each (9 ewes per treatment, 27 replications). Treatments were TMR (crude protein [CP] = 16.1, total digestible nutrients = 69.1%) moisture levels for 40%, 50%, and 60%. Results: No differences were found in body weight gain among all treatment groups (p>0.05). Nitrogen balance including digestible N, retained N, and urinary and fecal N showed no change among the treatment groups (p>0.05). Fresh water intake was the lower in 50% TMR moisture group than in the other groups (p<0.05). Other than ether extract which was higher in 60% TMR moisture group (p<0.05) the differences among nutrient digestibilities including CP, organic matter, dry matter, neutral detergent fiber, acid detergent fiber, and non-fiber carbohydrate were not significant (p>0.05). No significant difference was observed for serum protein, blood urea nitrogen, glucose, and triglyceride among the treatment groups (p>0.05). Wool and blood cortisol were not different among the treatment groups (p>0.05). Blood hematology including red blood cell, white blood cells, hemoglobin, hematocrit, basophils, and eosinophils were not different among the treatment groups (p>0.05). Conclusion: It is concluded that TMR moisture at 40%, 50%, and 60% had no effects on N balance parameters, and nutrient digestibilities except for the ether extract under hot and humid conditions. Additionally there were no effects on stress conditions include wool cortisol, as well as blood cortisol levels of ewes.

Effects of Chromium Methionine Supplementation on Blood Metabolites and Fatty Acid Profile of Beef during Late Fattening Period in Holstein Steers

Nejad, Jalil Ghassemi,Lee, Bae-Hun,Kim, Byong-Wan,Ohh, Sang-Jip,Sung, Kyung Il Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.3

The objective of this study was to determine the effects of chromium methionine (Cr-Met) chelate supplementation on blood metabolites and fatty acid profile of beef from Holstein steers during late fattening period. Fifteen Holstein steers were allotted randomly into two groups including the control (non Cr-Met feeding, NCM, ave. body weight [BW] = $483{\pm}25.7kg$) and the treatment (Cr-Met feeding for 4 months, 4CM, ave. $BW=486{\pm}27.5kg$) group. The feeding amount of Cr-Met to animals was limited to 400 ppb/cow/d and was supplemented to total mixed ration. No difference in blood albumin, alkaline phosphatase, urea-nitrogen, calcium, creatine, glucose, total protein, triglyceride, and cholesterol were observed between the treatment groups (p>0.05). The level of high density lipoprotein was higher in the 4CM group than the NCM group, whereas low density lipoprotein was lower in the 4CM group (p<0.05). The fatty acid composition (caprate, laurate, myristate, pentadecanoate, palmitate, palmitoleate, margarate, cis-11 heptadodecanoate, stearate, oleate, trans-vaccenate, linoleate, cis-11 eicosenoate, docosa hexaenoic acid, and docosa pentaenoic acid) of the beef showed no difference between the two groups (p>0.05). The arachidonic acid level tended to be higher in the 4CM than the NCM group (p = 0.07). Cr-Met had no influence (p>0.05) on the ratio of saturated, unsaturated, unsaturated/saturated, monounsaturated/saturated and polyunsaturated/saturated fatty acids whereas the ratio of polyunsaturated fatty acids (PUFA) in the 4CM group was comparatively higher than the NCM group (p<0.05). This study concluded that feeding Cr-Met supplementation in 400 ppb/d to Holstein steers for 4 months during late fattening period can improve some blood metabolites and beef quality by increasing PUFA and gamma-linoleate compositions of beef.

Bending analysis of bi-directional functionally graded Euler-Bernoulli nano-beams using integral form of Eringen's non-local elasticity theory

Nejad, Mohammad Zamani,Hadi, Amin,Omidvari, Arash,Rastgoo, Abbas Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.67 No.4

The main aim of this paper is to investigate the bending of Euler-Bernouilli nano-beams made of bi-directional functionally graded materials (BDFGMs) using Eringen's non-local elasticity theory in the integral form with compare the differential form. To the best of the researchers' knowledge, in the literature, there is no study carried out into integral form of Eringen's non-local elasticity theory for bending analysis of BDFGM Euler-Bernoulli nano-beams with arbitrary functions. Material properties of nano-beam are assumed to change along the thickness and length directions according to arbitrary function. The approximate analytical solutions to the bending analysis of the BDFG nano-beam are derived by using the Rayleigh-Ritz method. The differential form of Eringen's non-local elasticity theory reveals with increasing size effect parameter, the flexibility of the nano-beam decreases, that this is unreasonable. This problem has been resolved in the integral form of the Eringen's model. For all boundary conditions, it is clearly seen that the integral form of Eringen's model predicts the softening effect of the non-local parameter as expected. Finally, the effects of changes of some important parameters such as material length scale, BDFG index on the values of deflection of nano-beam are studied.

Beehive (Hexagrid), New Innovated Structural System for Tall Buildings

Nejad, Peyman Askari Council on Tall Building and Urban Habitat Korea 2016 International journal of high-rise buildings Vol.5 No.4

Tall Buildings have been one of the most prominent symbols of economic growth for nearly a century. Yet, in the aftermath of the tragedies of September 11, "signature" Tall buildings have become the focus of much debate. The structural systems today are undergoing a major evolution to address the ability of providing flexibility in the design and use of the building together with sustainability (Green) and cost-effective system. This paper describes a new invented structural system, evolutionary structural analysis and design of Tall buildings, which involves the entire analysis process, including conceptual and design stages and comparison with the existing Tall building. This study presents an new innovative structural system, Beehive (Hexagrid), for Tall buildings. The final results are achieved by modeling an 80 story Tall building with the optimized angle and topology of hexagon members by using a computer analysis, ETABS finite element analysis. The objective function of this system is to use one structural system in order to both maximize Eigen frequency for resisting dynamic responses and minimize mean compliance for static responses. Finite element analysis is carried out by using standardized materials. Optimal Hexagrid topologies with the highest stiffness are finally determined to resist both static and dynamic behaviors. Holistic design integration approaches between structures and facades to save energy for environmental control are studied. Innovative design ideas to control structural motion as well as to utilize that motion to harness energy are discussed. Considering abundant emergence of tall buildings all over the world in recent years, the importance of the studies presented in this paper cannot be overemphasized for constructing more sustainable built environments.

The Most Important Social Determinants of Slum Dwellers' Health: A Scoping Review

Nejad, Farhad Nosrati,Ghamari, Mohammad Reza,Kamal, Seyed Hossein Mohaqeqi,Tabatabaee, Seyed Saeed,Ganjali, Raheleh The Korean Society for Preventive Medicine 2021 Journal of Preventive Medicine and Public Health Vol.54 No.4

Objectives: Given the importance of social determinants of health in promoting the health of slum residents, this study was conducted with the aim of identifying the main dimensions and components of these determinants. Methods: This scoping review study was conducted according to the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews). A comprehensive search was performed of PubMed, ProQuest, Scopus, and Web of Science for articles conducted from 2010 to the end of 2019. Studies were selected based on inclusion criteria, with a special focus on studies dealing with the social determinants of physical and mental health or illness. Results: Thirty-three articles were selected to extract information on the social determinants of health. After reviewing the articles, 7 main dimensions (housing, socioeconomic status of the family, nutrition, neighborhood characteristics, social support and social capital, occupational factors, and health behaviors) and 87 components were extracted as social determinants of health among slum dwellers. Conclusions: This framework could be used by planners, managers, and policy-makers when making decisions affecting the health of these settlements' residents due to the common characteristics of slums around the world, especially in developing countries.

Effects of Water Restriction Following Feeding on Nutrient Digestibilities, Milk Yield and Composition and Blood Hormones in Lactating Holstein Cows Under Heat Stress Conditions

Nejad, Jalil Ghassemi,Lohakare, Jayant D.,West, Joe W.,Kim, Byong W.,Lee, Bae H.,Sung, Kyung I. Informa UK (Taylor Francis) 2015 Italian journal of animal science Vol.14 No.3

Effects of Feeding Levels of Starter on Weaning Age, Performance, Nutrient Digestibility and Health Parameters in Holstein Dairy Calves

Nejad, J. Ghassemi,Hosseindoust, A.,Shoae, A.,Ghorbani, B.,Lee, B.H.,Oskoueian, E.,Hajilari, D.,Amouzmehr, A.,Lohakare, J.D.,Sung, K.I. Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.6

To evaluate the effects of feeding four different levels of starter in male Holstein dairy calves, a completely randomized study was conducted, using 28 calves with initial body weight of $40.5{\pm}2.4$ kg. The animals were fed iso-nitrogenous starter and were weaned when they consumed 350, 500, 650 and 800 g/d of starter for 3 d consecutively. Starter and water were available ad-libitum throughout the experiment. Body weight at pre-weaning (less than 5 wk) and post-weaning (8 wk) was lower in calves that received 350 g/d of starter than in the other treatments (p<0.05). Feed conversion ratio (FCR) was the highest among all treatments in pre-weaning period (p<0.05). Dry matter intake (DMI) at weaning and total DMI was higher in that calves received 800 g/d of starter compared with other treatments (p<0.05). Calves fed 350 and 500 g/d of starter were weaned earlier (p<0.05) and showed lower milk consumption (kg, DM) compared with other treatments whereas no significant difference was observed between calves fed 350 and 500 g/d of starter (p>0.05). Dry matter, organic matter and crude protein digestibilities were lower in calves that received 350 g/d of starter compared with other treatments (p<0.05). No differences were observed in acid detergent and neutral detergent fiber digestibility among all treatments (p>0.05).Treatments had no significant effect on time of starting rumination, respiratory score, and days of drug administration for pneumonia. There were no meaningful differences in feces, fecal odor scores, body temperature, and days of drug administration for diarrhea among all treatments (p>0.05). Total dry matter intake at the end of experiment showed no significant difference among calves fed 600 and 800 g/d of starter, but calves fed 350 and 500 g/d of starter showed more dry matter (DM) intake than calves in the 600 and 800 g/d groups (p<0.05).

Effects of Processing of Starter Diets on Performance, Nutrient Digestibility, Rumen Biochemical Parameters and Body Measurements of Brown Swiss Dairy Calves

Nejad, J. Ghassemi,Torbatinejad, N.,Naserian, A.A.,Kumar, S.,Kim, J.D.,Song, Y.H.,Ra, C.S.,Sung, K.I. Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.7

In order to investigate the effect of physical forms of starter diets on performance, weaning age, nutrient digestibility and rumen biochemical factors, 24 female of neonatal Brown Swiss calves (average body weight of $39.5{\pm}1.2kg$) were randomly assigned to three treatments. Dietary treatments were mashed (MS), pelleted (PS), and texturized (TS) starter using 8 calves from birth till 90 days of age in each treatment. Diets were formulated to be iso-nitrogenous with 21% crude protein. Based on the experimental results, calves that received PS and TS diets, had significant higher average daily gain (ADG) than those receiving MS (p<0.01). Dry matter intake in calves fed PS and TS was greater than calves fed MS (p<0.05), but there was no significant difference in feed efficiency. Treatments had no effect on initiation of rumination. Weaning age of calves in MS was longer than the other two treatments (p<0.05). Crude protein and organic matter digestibility in MS treated calves were lower than other treatments (p<0.05). No differences were observed in neutral detergent fiber (NDF) and ash digestibility among treatments (p>0.05). Ruminal pH was higher (p<0.01) in MS than the other groups, but ruminal ammonia (g/dl) concentration was not different among the treatments. Body measurements such as body length, pin width, hip width, pin to hip length, size of metacarpus and metatarsus bones, hip height, wither height, stomach size and heart girth were not significantly different among the treatments. Overall, it is concluded that starter diets in the form of pellet and texture can improve performance in neonatal Brown Swiss calves compared to the mashed form.

Rate-based simulation and comparison of various promoters for CO2 capture in industrial DEA-promoted potassium carbonate absorption unit

Tohid Nejad Ghaffar Borhani,Vahid Akbari,Mohammad Kamaruddin Abdul Hamid,Zainuddin Abdul Manan 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.22 No.-

Diethanolamine (DEA)-promoted potassium carbonate process for CO2 removal is modelled using ratebasedapproach and Electrolyte NRTLmodel. Acceptable agreements between the simulation results andthe experimental data are achieved. The effectiveness of monoethanolamine (MEA), diglycolamine(DGA), diisopropanolamine (DIPA), and methyldiethanolamine (MDEA) as promoters are investigated. MEA shows promising performance for CO2 removal. The CO2 absorptions by DGA and DIPA are goodenough, but their prices are higher than MEA and DEA. The CO2 absorption byMDEA is not significant andit cannot be used as a promoter. A parametric study is performed to assess the effects of importantprocess parameters.