scholarly journals HUBUNGAN DENSITAS ENERGI DAN ASUPAN CAIRAN DENGAN BERAT JENIS URIN PADA REMAJA

2017 ◽  
Vol 6 (4) ◽  
pp. 326
Author(s):  
Liani Setyarsih ◽  
Martha Ardiaria ◽  
Deny Yudi Fitranti
Keyword(s):  
Physical Activity ◽  
Energy Density ◽  
Specific Gravity ◽  
Fluid Intake ◽  
Energy Content ◽  
High Energy ◽  
High Energy Density ◽  
Observational Research ◽  
Urine Specific Gravity ◽  
Hydration Status

Background: Hydration status is a condition that describes total body fluid. One of the method of measuring hydration status is urine specific gravity. Energy density of food is the amount energy content of total weight food. Foods with high energy density tend to have a lower water content, which will affect fluid intake. The aim of this research was to know the correlation of energy density and fluid intake with urine specific gravity as one of the markers of hydration status. Method: This was an observational research with cross-sectional study design. The research was conducted in Senior High School 15 Semarang involving 55 subjects by Simple Random Sampling method. Food intake and fluid intake were assessed by 1x24 hours Food Recall. Urine specific gravity measured in laboratory. Body fat percentage measured by BIA (Bioelectrical Impendance Analysis) and physical activity assessed by 1x24 hours record physical activity. Data were analyzed by rank spearman.Result: Median of urine specific gravity men and women was 1,02 g/ml. Mean of energy density in men was 1,8±0,32 kcal/gram, in women was 2,1±0,59 kkal/gram. Mean of fluid intake in men was 2406,4±491,38 ml, in women was 2159,5±648,42ml. There was significant correlation of fluid intake with hydration status (p=0,027). There was no significant correlation of energy density and hydration status (p=0,218). Multivariate analysis showed that 14,6% of hydration status is affected by both fluid intake and energy intake. Conclusion: There was significant correlation of fluid intake with urine specific gravity. There was no significant correlation of energy density and urine specific gravity.

Computational insights into novel dicobalt polynitrogen: structure, stability, intermolecular interaction, and application

2017 ◽  
Vol 95 (6) ◽  
pp. 656-663
Author(s):  
Tingting Zhu ◽  
Ping Ning ◽  
Jinhui Peng ◽  
Xiuying Zhang ◽  
Lihong Tang
Keyword(s):  
Energy Density ◽  
Intermolecular Interaction ◽  
Density Functional ◽  
Energy Content ◽  
Energetic Material ◽  
High Energy ◽  
High Energy Density ◽  
Structure Stability ◽  
Chemical Hardness ◽  
Covalent Interaction

Previous studies have suggested that polynitrogen species are significant as potential candidates for superior energetic material. In this paper, the polynitrogen species of Co2(N5)4 were reasonably designed and studied by the density functional theory (DFT), and five isomers of Co2(N5)4 were selected. These species were explored in detail, including structure, stability, intermolecular interaction, and application. The five isomers, each with its own special structure feature, were stable enough based on the analysis of bond energy, chemical hardness, and aromaticity. Furthermore, the intermolecular interactions suggested the presence of a covalent interaction in the Co–Co and N–N bonds, the electronic delocalization in cyclo-N5, and the ionic feature in the Co–N bond. In addition, all of the title species held high-energy content. Compared with the known high energy density materials of HB(N5)3Be2(N5)3BH, energetic material of nitromethane, and famous nitramine explosive HMX (1,3,5,7-tetranitro-1,3,5,7-tetrazocane), Co2(N5)4 holds a stronger advantage. The five Co2(N5)4 species were located at 27.8–35.8 kcal/mol per N2 unit, their energy densities were about 2.73 × 104 MJ/kg, and their mass densities were in the range of 2.60–2.74 g/cm3. Significantly, the 4-1 was the most stable, and its density was also the greatest among the five species. Thus, it has the most potential as a high energy density material.

scholarly journals Pregame Urine Specific Gravity and Fluid Intake by National Basketball Association Players During Competition

2009 ◽  
Vol 44 (1) ◽  
pp. 53-57 ◽  
Author(s):  
Kristin L. Osterberg ◽  
Craig A. Horswill ◽  
Lindsay B. Baker
Keyword(s):  
Specific Gravity ◽  
Fluid Intake ◽  
Volume Of Fluid ◽  
Cross Sectional Study ◽  
National Basketball Association ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Sweat Loss ◽  
Cross Sectional ◽  
Basketball Game

Abstract Context: Urine specific gravity (USG) has been used to estimate hydration status in athletes on the field, with increasing levels of hypohydration indicated by higher USG measurements (eg, greater than 1.020). Whether initial hydration status based on a urine measure is related to subsequent drinking response during exercise or athletic competition is unclear. Objective: To determine the relationship between pregame USG and the volume of fluid consumed by players in a professional basketball game. Design: Cross-sectional study. Setting: Basketball players were monitored during Summer League competition. Patients or Other Participants: Players (n  =  29) from 5 teams of the National Basketball Association agreed to participate. Main Outcome Measure(s): Pregame USG was measured for each player on 2 occasions. Athletes were given ad libitum access to fluid during each game and were unaware of the purpose of the study. Volume of fluid intake was measured for each player. To assess sweat loss, athletes were weighed in shorts before and after each game. Results: Sweat loss ranged from 1.0 to 4.6 L, with a mean sweat loss of 2.2 ± 0.8 L. Fluid intake ranged from 0.1 to 2.9 L, with a mean fluid intake of 1.0 ± 0.6 L. Pregame USG was greater than 1.020 in 52% of the urine samples collected and was not correlated with fluid volume consumed during either of the games (r  =  0.15, P  =  .48, and r  =  0.15, P  =  .52, respectively). Conclusions: Approximately half of the players began the games in a hypohydrated state, as indicated by USG. Fluid intake during the game did not compensate for poor hydration status before competition. Furthermore, sweat losses in these players during games were substantial (greater than 2 L in approximately 20 minutes of playing time). Therefore, both pregame and during-game hydration strategies, such as beverage availability and player education, should be emphasized.

scholarly journals Conversion of poplar biomass into high-energy density tricyclic sesquiterpene jet fuel blendstocks

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Gina M. Geiselman ◽  
James Kirby ◽  
Alexander Landera ◽  
Peter Otoupal ◽  
Gabriella Papa ◽  
...  
Keyword(s):  
Energy Density ◽  
Lignocellulosic Biomass ◽  
Energy Content ◽  
Carbon Sources ◽  
High Energy ◽  
Jet Fuel ◽  
Fuel Properties ◽  
Aviation Fuel ◽  
High Energy Density ◽  
Jet Fuels

Abstract Background In an effort to ensure future energy security, reduce greenhouse gas emissions and create domestic jobs, the US has invested in technologies to develop sustainable biofuels and bioproducts from renewable carbon sources such as lignocellulosic biomass. Bio-derived jet fuel is of particular interest as aviation is less amenable to electrification compared to other modes of transportation and synthetic biology provides the ability to tailor fuel properties to enhance performance. Specific energy and energy density are important properties in determining the attractiveness of potential bio-derived jet fuels. For example, increased energy content can give the industry options such as longer range, higher load or reduced takeoff weight. Energy-dense sesquiterpenes have been identified as potential next-generation jet fuels that can be renewably produced from lignocellulosic biomass. Results We developed a biomass deconstruction and conversion process that enabled the production of two tricyclic sesquiterpenes, epi-isozizaene and prespatane, from the woody biomass poplar using the versatile basidiomycete Rhodosporidium toruloides. We demonstrated terpene production at both bench and bioreactor scales, with prespatane titers reaching 1173.6 mg/L when grown in poplar hydrolysate in a 2 L bioreactor. Additionally, we examined the theoretical fuel properties of prespatane and epi-isozizaene in their hydrogenated states as blending options for jet fuel, and compared them to aviation fuel, Jet A. Conclusion Our findings indicate that prespatane and epi-isozizaene in their hydrogenated states would be attractive blending options in Jet A or other lower density renewable jet fuels as they would improve viscosity and increase their energy density. Saturated epi-isozizaene and saturated prespatane have energy densities that are 16.6 and 18.8% higher than Jet A, respectively. These results highlight the potential of R. toruloides as a production host for the sustainable and scalable production of bio-derived jet fuel blends, and this is the first report of prespatane as an alternative jet fuel.

scholarly journals Fluid consumption, hydration status, and its associated factors: a cross sectional study among medical students in Palembang, Indonesia

2021 ◽  
Vol 5 (1) ◽  
pp. 88
Author(s):  
Dwi Lisa Nur'aini ◽  
Ardesy Melizah Kurniati ◽  
Moretta Damayanti ◽  
Syarif Husin ◽  
Joko Marwoto
Keyword(s):  
Physical Activity ◽  
Medical Students ◽  
Specific Gravity ◽  
Associated Factors ◽  
Cross Sectional Study ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Fluid Consumption ◽  
Sectional Study ◽  
Cross Sectional

Background: Adequate fluid consumption and hydration status of students become a special concern because being dehydrated by just 1%-2% can impair cognitive performance. The objectives of this study were to assess the daily fluid consumption, and analyze the correlation of fluid consumption and other associated factors with hydration status of medical students in Universitas Sriwijaya.Methods: A total of 93 medical students in Universitas Sriwijaya were recruited to complete a 7-day cross-sectional study. Subjects were asked to complete a self-administered 7-day-24-hours fluid record and provide first morning urine sample on the last day. Gender information was collected. Physical activity was evaluated by self-administered long version of IPAQ. Body mass index was calculated using body weight and body height measurement. Urine specific gravity was determined by urinometer. The 7-day-24-hours fluid record and 1-day-24-hours urine specific gravity were calculated and analyzed.Results: Majority of the subjects were well hydrated, while 10.8% were slightly dehydrated, 6.5% were moderately dehydrated and 9.7% were severely dehydrated. The average of daily fluid consumption was 1789.28 (989.3-2930) mL. Coefficient correlation of fluid consumption from beverages with urine specific gravity was -0.651 (p=0.00) by Pearson correlation test. The hydration status showed no association with gender, physical activity and body mass index.Conclusions: Most subjects in this study were well hydrated. A strong association was found between fluid consumption and hydration status. It was feasible to use daily fluid consumption from beverages to predict hydration status.

scholarly journals Hydration Status in Adolescent Alpine Skiers During a Training Camp

2021 ◽  
Vol 79 (1) ◽  
pp. 55-63
Author(s):  
Dirk Aerenhouts ◽  
Laurent Chapelle ◽  
Peter Clarys ◽  
Evert Zinzen
Keyword(s):  
Specific Gravity ◽  
Fluid Intake ◽  
Training Session ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Fluid Loss ◽  
Individual Values ◽  
Training Camp ◽  
Ad Libitum ◽  
Alpine Skiers

Abstract Maintaining euhydration is important for optimal health, performance and recovery, but can be challenging for alpine skiers when training in a relatively cold but dry environment. This study aimed to evaluate hydration status, fluid loss and fluid intake in adolescent alpine skiers during a training camp. Twelve athletes aged 14.3 ± 0.9 years volunteered to participate in the study. Athletes resided at an altitude of 1600 m and trained between 1614 and 2164 m. During eight consecutive days, urine specific gravity was measured before each morning training session using a refractometer. Changes in body weight representing fluid loss and ad libitum fluid intake during each morning training session were assessed using a precision scale. Mean pre-training urine specific gravity remained stable throughout the training camp. Individual values ranged between 1.010 and 1.028 g/cm3with 50 to 83% of athletes in a hypohydrated state (urine specific gravity ≥ 1.020 g/cm3). Mean training induced fluid loss remained stable throughout the training camp (range -420 to -587 g) with individual losses up to 1197 g (-3.5%). Fluid intake was significantly lower than fluid loss during each training session. To conclude, urine specific gravity values before training indicated insufficient daily fluid intake in more than half of the athletes. Furthermore, fluid intake during training in adolescent alpine skiers was suboptimal even when drinks were provided ad libitum. Coaches and athletes should be encouraged to carefully monitor hydration status and to ensure that alpine skiers drink sufficiently during and in between training sessions.

Dealing with Obesity: An Australian Perspective

2003 ◽  
Vol 15 (1_suppl) ◽  
pp. S33-S36
Author(s):  
S Pal ◽  
G Egger ◽  
G Wright
Keyword(s):  
Physical Activity ◽  
Type 2 Diabetes ◽  
Energy Density ◽  
Heart Diseases ◽  
Population Level ◽  
High Energy ◽  
Modern Technology ◽  
High Energy Density ◽  
Obesogenic Environment

Over half of all Australians are classified as overweight or obese and this is increasing by 1% of the population per year. Obesity is linked with a range of health ailments including type 2 diabetes, heart diseases and some cancers. At a population level it is well accepted that obesity is a result of the increasing use of modern technology, resulting in decreased energy expenditure, in combination with easily available high energy density foods, the “obesogenic environment”. In the modern environment, there are two major areas of management to assist the overweight and obese. Both include a change in lifestyle. Future strategies in weight management should include reduction in energy density and increase in daily physical activity.

Urine Specific Gravity as a Practical Marker for Identifying Suboptimal Fluid Intake of Runners ∼12-hr Postexercise

2019 ◽  
Vol 29 (1) ◽  
pp. 32-38
Author(s):  
Eric Kyle O’Neal ◽  
Samantha Louise Johnson ◽  
Brett Alan Davis ◽  
Veronika Pribyslavska ◽  
Mary Caitlin Stevenson-Wilcoxson
Keyword(s):  
Specific Gravity ◽  
Body Mass ◽  
Fluid Intake ◽  
Area Under The Curve ◽  
Fluid Replacement ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Accuracy Score ◽  
Characteristic Area ◽  
Almost All

The legitimacy of urine specific gravity (USG) as a stand-alone measure to detect hydration status has recently been challenged. As an alternative to hydration status, the purpose of this study was to determine the diagnostic capability of using the traditional USG marker of >1.020 to detect insufficient recovery fluid consumption with consideration for moderate versus high sweat losses (2.00–2.99 or >3% body mass, respectively). Adequate recovery fluid intake was operationally defined as ≥100% beverage fluid intake plus food water from one or two meals and a snack. Runners (n = 59) provided 132 samples from five previous investigations in which USG was assessed 10–14 hr after 60–90 min runs in temperate-to-hot environments. Samples were collected after a meal (n = 58) and after waking (n = 74). When sweat losses exceeded 3% body mass (n = 60), the relationship between fluid replacement percentage and USG increased from r = −.55 to −.70. Correct diagnostic decision improved from 66.6 to 83.3%, and receiver operating characteristic area under the curve increased the diagnostic accuracy score from 0.76 to approaching excellent (0.86). Artifacts of significant prerun hyperhydration (eight of 15 samples has USG <1.005) may explain false positive diagnoses, while almost all (84%) cases of false positives were found when sweat losses were <3.0% of body mass. Evidence from this study suggests that euhydrated runners experiencing significant sweat losses who fail to reach adequate recovery fluid intake levels can be identified by USG irrespective of acute meal and fluid intake ∼12-hr postrun.

scholarly journals Fluid consumption, hydration status, and its associated factors: a cross sectional study among medical students in Palembang, Indonesia

2020 ◽  
Vol 4 (1-3) ◽  
pp. 43
Author(s):  
Ardesy Melizah Kurniati ◽  
Moretta Damayanti ◽  
Nur Mahmudah
Keyword(s):  
Physical Activity ◽  
Medical Students ◽  
Specific Gravity ◽  
Associated Factors ◽  
Cross Sectional Study ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Fluid Consumption ◽  
Sectional Study ◽  
Cross Sectional

Background: Adequate fluid consumption and hydration status of students become a special concern because being dehydrated by just 1%-2% can impair cognitive performance. The objectives of this study were to assess the daily fluid consumption, and analyze the correlation of fluid consumption and other associated factors with hydration status of medical students in Universitas Sriwijaya.Methods: A total of 93 medical students in Universitas Sriwijaya were recruited to complete a 7-day cross-sectional study. Subjects were asked to complete a self-administered 7-day-24-hours fluid record and provide first morning urine sample on the last day. Gender information was collected. Physical activity was evaluated by self-administered long version of IPAQ. Body mass index was calculated using body weight and body height measurement. Urine specific gravity was determined by urinometer. The 7-day-24-hours fluid record and 1-day-24-hours urine specific gravity were calculated and analyzed.Results: Majority of the subjects were well hydrated, while 10.8% were slightly hydrated, 6.5% were moderately hydrated and 9.7% were severely dehydrated. The average of daily fluid consumption was 1789.28 (989.3-2930) mL. Coefficient correlation of fluid consumption from beverages with urine specific gravity was -0.651 (p=0.00) by Pearson correlation test. The hydration status showed no association with gender, physical activity and body mass index.Conclusions: Most subjects in this study were well hydrated. A strong association was found between fluid consumption and hydration status. It was feasible to use daily fluid consumption from beverages to predict hydration status.

scholarly journals Generation of H2 on Board Lng Vessels for Consumption in the Propulsion System

2020 ◽  
Vol 27 (1) ◽  
pp. 83-95
Author(s):  
Ignacio Arias Fernández ◽  
Manuel Romero Gómez ◽  
Javier Romero Gómez ◽  
Luis M. López-González
Keyword(s):  
Energy Density ◽  
Energy Efficient ◽  
Storage Systems ◽  
Energy Content ◽  
Storage System ◽  
High Energy ◽  
High Energy Density ◽  
Injection System ◽  
Gas Combustion ◽  
Safety Hazard

AbstractAt present, LNG vessels without reliquefaction plants consume the BOG (boil-off gas) in their engines and the excess is burned in the gas combustion unit without recovering any of its energy content. Excess BOG energy could be captured to produce H2, a fuel with high energy density and zero emissions, through the installation of a reforming plant. Such H2 production would, in turn, require on-board storage for its subsequent consumption in the propulsion plant when navigating in areas with stringent anti-pollution regulations, thus reducing CO2 and SOX emissions. This paper presents a review of the different H2 storage systems and the methods of burning it in propulsion engines, to demonstrate the energetic viability thereof on board LNG vessels. Following the analysis, it is identified that a pressurised and cooled H2 storage system is the best suited to an LNG vessel due to its simplicity and the fact that it does not pose a safety hazard. There are a number of methods for consuming the H2 generated in the DF engines that comprise the propulsion plant, but the use of a mixture of 70% CH4-30% H2 is the most suitable as it does not require any modifications to the injection system. Installation of an on-board reforming plant and H2 storage system generates sufficient H2 to allow for almost 3 days’ autonomy with a mixture of 70%CH4-30%H2. This reduces the engine consumption of CH4 by 11.38%, thus demonstrating that the system is not only energy-efficient, but lends greater versatility to the vessel.

Human Hydration Indices: Acute and Longitudinal Reference Values

2010 ◽  
Vol 20 (2) ◽  
pp. 145-153 ◽  
Author(s):  
Lawrence E. Armstrong ◽  
Amy C. Pumerantz ◽  
Kelly A. Fiala ◽  
Melissa W. Roti ◽  
Stavros A. Kavouras ◽  
...  
Keyword(s):  
Specific Gravity ◽  
Body Mass ◽  
Reference Values ◽  
Fluid Intake ◽  
Pure Water ◽  
Urine Volume ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Total Fluid Intake ◽  
Free Living

It is difficult to describe hydration status and hydration extremes because fluid intakes and excretion patterns of free-living individuals are poorly documented and regulation of human water balance is complex and dynamic. This investigation provided reference values for euhydration (i.e., body mass, daily fluid intake, serum osmolality; M ± SD); it also compared urinary indices in initial morning samples and 24-hr collections. Five observations of 59 healthy, active men (age 22 ± 3 yr, body mass 75.1 ± 7.9 kg) occurred during a 12-d period. Participants maintained detailed records of daily food and fluid intake and exercise. Results indicated that the mean total fluid intake in beverages, pure water, and solid foods was >2.1 L/24 hr (range 1.382–3.261, 95% confidence interval 0.970–3.778 L/24 hr); mean urine volume was >1.3 L/24 hr (0.875–2.250 and 0.675–3.000 L/24 hr); mean urine specific gravity was >1.018 (1.011–1.027 and 1.009–1.030); and mean urine color was ≥4 (4–6 and 2–7). However, these men rarely (0–2% of measurements) achieved a urine specific gravity below 1.010 or color of 1. The first morning urine sample was more concentrated than the 24-h urine collection, likely because fluids were not consumed overnight. Furthermore, urine specific gravity and osmolality were strongly correlated (r2 = .81–.91, p < .001) in both morning and 24-hr collections. These findings provide euhydration reference values and hydration extremes for 7 commonly used indices in free-living, healthy, active men who were not exercising in a hot environment or training strenuously.

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