Decrease Energy Costs Research Articles

Alternative Work Schedules in Local Government: Cui Bono?

Recently there has been an increase in the number of cities contemplating and implementing alternative work schedules, particularly compressed workweeks, often to decrease energy costs for the organization or to decrease transportation and fuel costs for employees. Although many organizations offer alternative work schedules, there is little research on the benefits and drawbacks of these schedules. This research endeavors to fill that gap in our understanding by providing the results of a recent survey of human resources directors in 151 U.S. cities with populations more than 25,000 about their experience with the benefits and drawbacks of alternative work schedules. More than half (56.3%) of the cities surveyed reported offering some form of alternative work schedule, with compressed workweeks being the most commonly offered. Although drawbacks were noted, the human resources directors were more likely to report benefits for employees and the organization in offering alternative work schedules.

Laetoli Footprints Preserve Earliest Direct Evidence of Human-Like Bipedal Biomechanics

BackgroundDebates over the evolution of hominin bipedalism, a defining human characteristic, revolve around whether early bipeds walked more like humans, with energetically efficient extended hind limbs, or more like apes with flexed hind limbs. The 3.6 million year old hominin footprints at Laetoli, Tanzania represent the earliest direct evidence of hominin bipedalism. Determining the kinematics of Laetoli hominins will allow us to understand whether selection acted to decrease energy costs of bipedalism by 3.6 Ma.Methodology/Principal FindingsUsing an experimental design, we show that the Laetoli hominins walked with weight transfer most similar to the economical extended limb bipedalism of humans. Humans walked through a sand trackway using both extended limb bipedalism, and more flexed limb bipedalism. Footprint morphology from extended limb trials matches weight distribution patterns found in the Laetoli footprints.ConclusionsThese results provide us with the earliest direct evidence of kinematically human-like bipedalism currently known, and show that extended limb bipedalism evolved long before the appearance of the genus Homo. Since extended-limb bipedalism is more energetically economical than ape-like bipedalism, energy expenditure was likely an important selection pressure on hominin bipeds by 3.6 Ma.

Biocatalytic desulfurization (BDS) of petrodiesel fuels

Oil refineries are facing many challenges, including heavier crude oils, increased fuel quality standards, and a need to reduce air pollution emissions. Global society is stepping on the road to zero-sulfur fuel, with only differences in the starting point of sulfur level and rate reduction of sulfur content between different countries. Hydrodesulfurization (HDS) is the most common technology used by refineries to remove sulfur from intermediate streams. However, HDS has several disadvantages, in that it is energy intensive, costly to install and to operate, and does not work well on refractory organosulfur compounds. Recent research has therefore focused on improving HDS catalysts and processes and also on the development of alternative technologies. Among the new technologies one possible approach is biocatalytic desulfurization (BDS). The advantage of BDS is that it can be operated in conditions that require less energy and hydrogen. BDS operates at ambient temperature and pressure with high selectivity, resulting in decreased energy costs, low emission, and no generation of undesirable side products. Over the last two decades several research groups have attempted to isolate bacteria capable of efficient desulfurization of oil fractions. This review examines the developments in our knowledge of the application of bacteria in BDS processes, assesses the technical viability of this technology and examines its future challenges.

Limiting factors in peak oxygen uptake and the relationship with functional ambulation in ambulating children with Spina Bifida

The objective of this study is to interpret the outcomes of peak oxygen uptake (VO(2peak)) in children with SB and explore the relationship between VO(2peak) and functional ambulation using retrospective cross-sectional study. Twenty-three ambulating children with SB participated at Wilhelmina's Children's Hospital Utrecht, the Netherlands. VO(2peak) was measured during a graded treadmill-test. Eschenbacher's and Maninna's algorithm was used to determine limiting factors in reaching low VO(2peak) values. Energy expenditure during locomotion (both O(2) rate and O(2) cost) and percentage of VO(2peak) and HR(peak) were determined during a 6-min walking test (6MWT). Differences between community and normal ambulators were analyzed. VO(2peak), VO(2peak)/kg, HR(peak), RER(peak) and VE (peak) were significantly lower compared to reference values, with significant differences between normal and community ambulators. Limiting factors according to the algorithm were mostly "muscular and/or deconditioning" (47%) and ventilatory "gasexchange" (35%). Distance walked during 6MWT was 48.5% of predicted distance. Both O(2) rate and O(2) cost were high with significant differences between normal and community ambulators [17.6 vs. 21.9 ml/(kg min) and 0.27 vs 0.43 ml/(kg m)]. Also %HR(peak) and %VO(2peak) were significantly higher in community ambulators when compared to normal ambulators (resp. 97.6 vs. 75% and 90.2 vs. 55.9%). VO(2peak) seems to be mostly limited by deconditioning and/or muscular components and possible ventilatory factors. For both peak values and functional ambulation, community ambulators were significantly more impaired than normal ambulators. High energy expenditure, %VO(2peak) and %HR(peak) reflect high level of strain during ambulation in the community ambulators. Future exercise testing in children with SB should include assessment of ventilatory reserve. Exercise training in ambulatory children should focus on increasing both VO(2peak) and muscular endurance, as well as decreasing energy cost of locomotion.

Effect of Fastskin Suits on Performance, Drag, and Energy Cost of Swimming

To investigate the effect of fastskin suits on 25- to 800-m performances, drag, and energy cost of swimming. The performances, stroke rate and distance per stroke, were measured for 14 competitive swimmers in a 25-m pool, when wearing a normal suit (N) and when wearing a full-body suit (FB) or a waist-to-ankle suit (L). Passive drag, oxygen uptake, blood lactate, and the perceived exertion were measured in a flume. There was a 3.2% +/- 2.4% performance benefit for all subjects over the six distances covered at maximal speed wearing FB and L when compared with N. When wearing L, the gain was significantly lower (1.8% +/- 2.5%, P < 0.01) than when wearing FB compared with N. The exercise perception was significantly lower when wearing FB than N, whereas there was no statistical difference when wearing L. The distance per stroke was significantly higher when wearing FB and L, whereas the differences in stroke rate were not statistically significant. There was a significant reduction in drag when wearing FB and L of 6.2% +/- 7.9% and 4.7% +/- 4.4%, respectively (P < 0.01), whereas the energy cost of swimming was significantly reduced when wearing FB and L by 4.5% +/- 5.4% and 5.5% +/- 3.1%, respectively (P < 0.01). However, the differences between FB and L were not statistically significant for drag and oxygen uptake. FB and L significantly reduced passive drag, and this was associated with a decreased energy cost of submaximal swimming and an increased distance per stroke, at the same stroke rates, and reduced freestyle performance time.

Lateral stabilization improves walking in people with myelomeningocele

Muscle weakness and sensory deficits in people with myelomeningocele (MMC) make their walking control a greater challenge. We know little about how people with MMC optimize their walking balance. Recently, researchers have argued that medial–lateral control of gait requires more active neural input than the anterior–posterior direction, which is more passive. Our goal was to investigate the effect of providing external lateral stabilization (ELS) on walking patterns in people with MMC. We examined 12 people with MMC who could perform at least 4–6 independent steps. We found that the normalized step width (SW) was decreased 20% from without stabilizer to with stabilizer, where as the normalized step length (SL) was increased 4.17% from without stabilizer to with stabilizer. The ELS resulted in 25.10% reduction in centre of mass (COM) ranges of motions in the medial–lateral direction and 13.43% reduction in pelvic range of motions in the frontal plane. Our results suggested that by decreasing the medial–lateral control demands in people with MMC, we could improve gait with smaller SW, longer SL as well as reduced COM and pelvic ranges of motion in the frontal plane. In addition, ELS decreased energy cost and muscle co-activation of soleus and vastus lateralis that may help in diminishing the chances of pain and fatigue in people with MMC. Exploring the effect of the ELS provided us information that might be used to increase mobility safety and to develop a superior rehabilitation intervention for people with MMC.

Decreased Energy Cost and Improved Gait Pattern Using a New Orthosis in Persons With Long-Term Stroke

Thijssen DH, Paulus R, van Uden CJ, Kooloos JG, Hopman MT. Decreased energy cost and improved gait pattern using a new orthosis in persons with long-term stroke. Objective To measure energy cost and gait analysis in persons with stroke with and without a newly developed orthosis. Design Immediate and long-term (3wk) intervention (before-after trial). Setting University medical center. Participants Volunteer sample of 27 persons with long-term (range, 0.6–19y) hemiparetic stroke. Intervention Three-week familiarization to the new walking aid. Main Outcome Measures Energy cost (per distance walked), preferred walking speed (PWS), and step length. Energy cost was examined in all subjects while walking on a treadmill at 3 different velocities (PWS, PWS+30%, PWS−30%) during 3 different situations (without orthosis, with orthosis, after 3-wk orthosis familiarization). Spatiotemporal aspects of the gait pattern were examined using a 6-m instrumented walkway system. Results Using the orthosis immediately decreased energy cost in persons with stroke during walking at the PWS ( P<.001) and significantly increased walking speed ( P<.005) and step length ( P<.001). After 3 weeks of familiarization to the orthosis, energy cost at the PWS and at PWS+30% showed further improvement in energy cost ( P<.05). Conclusions The newly developed orthosis immediately decreases energy cost and improves walking speed and step length in persons with long-term stroke. After only 3 weeks of orthosis familiarization, energy cost shows additional improvement.

Effect of glycerol on pellet mill production efficiency (2007)

Crude glycerol is a by-product of the biofuels industry, which has the potential to be used as a feed ingredient in animal diets. However, little is known about glycerol’s nutritional value or how it impacts feed quality and feed processing efficiency. Three experiments were conducted to evaluate the effects of glycerol on production efficiency of a pellet mill. In all three experiments, diets were manufactured, pelleted, and data collected at the KSU Grain Science Feed Mill. All diets were steam conditioned to 85°F and pelleted at 150°F using a CPM pellet mill equipped with a 4 mm × 32 mm pellet die. In Exp. 1, the six treatments were a corn-soybean meal-based swine grower diet formulated to contain 0, 3, 6, 9, 12, and 15% crude glycerol. Experiment 2 included seven treatments: the control with no added soy oil or glycerol, the control diet with 3 or 6% added soy oil, the control diet with 3 or 6% added glycerol, and the control with 6 or 12% of a 50:50 soy oil to glycerol blend. Experiment 3 included five treatments: a control with no added lactose or glycerol, the control diet with 3.6 or 7.2% lactose, or the control with 3.6 or 7.2% glycerol. Each experimental diet was replicated by manufacturing a new batch of feed three times. Glycerol lowered delta temperature, amperage, and motor load in Exp. 1, 2, and 3. The addition of glycerol consistently improved pellet quality. Production rate was not affected by the addition of glycerol; however, glycerol decreased total energy usage (KWh/t). Furthermore, glycerol can be added to a diet in combination with soy oil in a blend to improve production efficiency and pellet quality compared to a diet containing only soy oil. The addition of glycerol will improve the production efficiency of pelleting, pellet quality, and decrease energy cost when included in diets prior to pelleting.

Harmonising climate change adaptation and mitigation: The case of tourist resorts in Fiji

Tourism in island states is vulnerable to climate change because it may result in detrimental changes in relation to extreme events, sea level rise, transport and communication interruption. This study analyses adaptation to climate change by tourist resorts in Fiji, as well as their potential to reduce climate change through reductions in carbon dioxide emissions. Interviews, site visitations, and an accommodation survey were undertaken. Many operators already prepare for climate-related events and therefore adapt to potential impacts resulting from climate change. Reducing emissions is not important to operators; however, decreasing energy costs for economic reasons is practised. Recommendations for further initiatives are made and synergies between the adaptation and mitigation approaches are explored.

Water desalination as a long-term sustainable solution to alleviate global freshwater scarcity? A North-South approach

The direct per capita availability of freshwater resources decreases as the world population continues its growth. This fact threatens the well-being and subsequently the survival ofhumanity as a whole. In this article, the North-South approach is used to raise certain questions on the significance of scarcity. Indeed, the issue of water for tourists might seem far removed from water scarcities for poor people in the South. If we assume a technological trajectory of decreased monetary costs, decreased energy costs per cubic metre, and moreover increased share of renewable energies in desalination (a kind of win-win-win scenario), does this mean that water for urban use of poor people in the world will cease to be a problem? Will not the energy costs remain too high? An approach based on the “basic needs” scenario is relevant to address these questions. The Canary Island of Lanzarote (Spain) and the city of Ladyoune, (Moroccan Sahara) are taken as explanatory case studies.

Comparison of three ankle—foot orthosis configurations for children with spastic diplegia

This study compared the functional efficacy of three commonly prescribed ankle–foot orthosis (AFO) configurations (solid [SAFO], hinged [HAFO], and posterior leaf spring [PLS]). Sixteen independently ambulatory children (10 males, six females; mean age 8 years 4 months, SD 2 years 4 months; range 4 years 4 months to 11 years 6 months) with spastic diplegia participated in this study. Four children were classified at level I of the Gross Motor Function Classification System (GMFCS; Palisano et al. 1997); the remaining 12 were at level II. Children were assessed barefoot (BF) at baseline (baseline assessment of energy consumption was performed with shoes on, no AFO) and in each orthotic configuration after three months of use, using gait analysis, oxygen consumption, and functional outcome measures. AFO use did not markedly alter joint kinematics or kinetics at the pelvis, hip, or knee. All AFO configurations normalized ankle kinematics in stance, increased step/stride length, decreased cadence, and decreased energy cost of walking. Functionally, all AFO configurations improved the execution of walking/running/jumping skills, upper extremity coordination, and fine motor speed/dexterity. However, the quality of gross motor skill performance and independence in mobility were unchanged. These results suggest that most children with spastic diplegia benefit functionally from AFO use. However, some children at GMFCS level II demonstrated a subtle but detrimental effect on function with HAFO use, shown by an increase in peak knee extensor moment in early stance, excessive ankle dorsiflexion, decreased walking velocity, and greater energy cost. Therefore, constraining ankle motion by using a PLS or SAFO should be considered for most, but not all, children with spastic diplegia.

Water desalination as a long-term sustainable solution to alleviate global freshwater scarcity? A North-South approach,

As sustainability cannot be imposed in a dictatorial manner but only learnt, society requires methods to make such learning effective at the societal level. Therefore, under such perspective, sustainability could be viewed as a “reflexive learning process”. This is exactly what this paper intends to deliver, especially to the scientific community striving to alleviate the freshwater scarcity crisis. However, in order to fully embrace the concept of sustainable water management, one should look beyond the limits of technology. This work, therefore, freely overshoots the scope of desalination technology as such. The direct per capita availability of freshwater resources decreases as the world population continues its growth. This fact threatens not only future economic growth expectations but also more importantly the well being and subsequently the survival of humanity as a whole. In the present debate, the Canary Island of Lanzarote (Spain) and the City of Laâyoune (Moroccan Sahara) are taken as case studies. The North-South approach is used to raise certain questions on the significance of scarcity. Indeed, the issue of “water for tourists” might seem far removed from water scarcities for poor people in the South. If we assume a technological trajectory or decreased monetary costs, decreased energy costs per cubic metre, and moreover increased share of renewable energies in desalination (a kind of win-win-win scenario), does this mean that water for urban use of poor people in the world will cease to be a problem? Will not the energy costs remain too high, anyway? Here, an approach from the “basic needs” scenario (free lifeline, in South Africa) is relevant.

Water desalination as a long-term sustainable solution to alleviate global freshwater scarcity? A North-South approach

As sustainability cannot be imposed in a dictatorial manner but only learnt, society requires methods to make such learning effective at the societal level. Therefore, under such perspective, sustainability could be viewed as a “reflexive learning process”. This is exactly what this paper intends to deliver, especially to the scientific community striving to alleviate the freshwater scarcity crisis. However, in order to fully embrace the concept of sustainable water management, one should look beyond the limits of technology. This work, therefore, freely overshoots the scope of desalination technology as such. The direct per capita availability of freshwater resources decreases as the world population continues its growth. This fact threatens not only future economic growth expectations but also more importantly the well being and subsequently the survival of humanity as a whole. In the present debate, the Canary Island of Lanzarote (Spain) and the City of Laâyoune (Moroccan Sahara) are taken as case studies. The North-South approach is used to raise certain questions on the significance of scarcity. Indeed, the issue of “water for tourists” might seem far removed from water scarcities for poor people in the South. If we assume a technological trajectory or decreased monetary costs, decreased energy costs per cubic metre, and moreover increased share of renewable energies in desalination (a kind of win-win-win scenario), does this mean that water for urban use of poor people in the world will cease to be a problem? Will not the energy costs remain too high, anyway? Here, an approach from the “basic needs” scenario (free lifeline, in South Africa) is relevant.

Technical Perspective Functional Electrical Stimulation For Augmented Walking In Adolescents With Incomplete Spinal Cord Injury

Background/Objective: This study evaluated the effects of functional electrical stimulation (FES) applied to the muscles acting on the pelvis, hip, and knee on muscle strength, energy cost of walking, maximum walking distance and speed, step length and cadence, and joint kinematics during gait in 3 ambulatory adolescents with incomplete spinal cord injury (SCI).Methods: Percutaneous FES was used to strengthen weakened muscles and to augment walking. After training, participants walked as desired at home with FES for 1 year. Data were collected at baseline (preintervention), and with FES on and FES off immediately following the training period and with FES on and FES off at 3, 6, and 12 months posttraining.Results: Voluntary strength improved in 12 out of 13 stimulated muscles. Decreased energy cost, increased maximum walking distance and speed, increased step length, and improved joint kinematics during gait were demonstrated with FES on and FES off Discussion: FES was able to achieve selective stimulation of key weakened muscles for augmented walking. The data suggest that FES had both direct and carryover effects.

Energy Costs, Endogenous Innovation, and Long-run Growth / Energiekosten, endogener technischer Fortschritt und Wirtschaftswachstum

Summary Based on the observation that energy costs have been decreasing over much of the 20th century, this paper extends the Romer (1990) model of endogenous technological change to examine the impact of secular changes in energy costs on technological progress and long-run growth. The key finding is that decreasing energy costs, while unambiguously increasing the rate of growth of output, enhance or reduce the rate of technological progress depending on the representative household's elasticity of marginal utility. A calibration exercise shows that even if technological progress is actually neither enhanced nor reduced, the endogenous innovation model of growth predicts a substantially stronger effect of energy costs on growth than the neoclassical model.

Front End to Backpipe: Membrane Technology in the Starch Processing Industry

The starch processing industry is characterized by streams that vary in diversity and complexity and that require extensive processing to achieve high end product quality. Water removal and product separations are two fundamental processing steps that impact product quality and processing economics. Many uses have been found for membrane technology in the starch processing industry; these include pretreatment of fresh water, recovery of solids and wastewater treatment. In many cases, membrane applications have increased quality of products, decreased energy costs and reduced disposal issues relating to waste treatment. Membranes can be used to filter many types of fluids in potato, wheat and corn starch isolation processes with varying degrees of success. Robust membrane materials have been developed with unique processing capabilities suited for the needs of the starch processing industry. Membranes have been used commercially to increase product quality while reducing costs, such as in syrup and sweetener clarification. Membrane technology has shown promise for reducing evaporation costs, improving product recovery and removing solids prior to wastewater treatment. In many applications, the cost of dewatering using membranes was a fraction of the cost of traditional methods. Membranes can be used to recover proteins from dilute process streams, but more work is needed regarding changes in nutrient quality when membranes are used in place of conventional separation technologies such as centrifugation, vacuum belt filtration and evaporation. There is need for detailed discussion of analyses regarding economics of long term operation and maintenance of membranes as part of a processing system.

Energy partitioning in torpor-sensitive and torpor-resistant deer mice (Peromyscus maniculatus)

We examined metabolic rates in 25 deer mice, Peromyscus maniculatus nebrascensis, held at an ambient temperature of 10 °C and found that all of them had the ability to enter torpor. However, we found a gradation between the most torpor-sensitive and the most torpor-resistant animals, suggesting that the expression of torpor is more than a simple all-or-nothing phenomenon. On a daily basis, the most torpor-sensitive and torpor-resistant mice partition energy similarly when food is not restricted. On restricted food, both groups of mice decrease the amount of time spent active and increase the amount of time spent at rest and in torpor. In addition, both groups of mice decrease oxygen-consumption rates and body temperatures during rest and the most torpor-sensitive mice further decrease energy costs by entering longer and deeper bouts of torpor. However, the overall energy saving due to torpor is only about 6%. Thus, the widely held view that the adaptive advantage of daily torpor is a large energy saving may be open to question. Alternatively, daily torpor may be important for reducing the rate of energy turnover when these small rodents must rely on body fat reserves.

Updating a steel mill power system to improve reliability and decrease energy costs

The cost of electricity and operating reliability in heavy industry can be key in determining which processes and plants survive in today's competitive market. This paper provides an insight into the planning and implementation of several significant cost saving and reliability improvements at a turn-of-the-century steel mill in Ohio. A clear understanding of what to look for and how to proceed with such projects should provide motivation for others considering similar improvements.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

New moisture meter could curb overdrying of walnuts

Tests of a new walnut moisture meter showed that it could help dryer operators prevent over-drying, which in turn would reduce drying time, decrease energy costs and increase revenue.

Energy-conservation measures for indoor swimming pools

We present a methodology for estimating heat losses for indoor swimming pools and energy savings associated with the adoption of selected energy-conservation strategies and devices in natatoriums. Although results are given for selected geographic locations, the methodology is generally applicable. Energy-conservation measures that reduce ventilation requirements are the most effective in decreasing energy costs for heating natatoriums. Pool covers are shown to save energy when the installation is accompanied by lower ventilation rates. At the present time, commercially available solar pool-heating systems are not economical for the climate of St. Louis compared to heating with natural gas but are marginally competitive with oil-fired heating systems.