Analysis of panel dent resistance

An analytical technique for elastic-plastic deformation of panels was developed, which is employed to analyze the denting mechanisms of panels resulting from point projectile impacts and impulsive loadings. The correlations of analytical results with the experimental measurements are considered quite satisfactory. The effect of elastic springback on the dent resistance analysis is found to be very significant for the panel (122 cm x 60.9 cm x 0.076 cm) subjected to a point projectile impact at 16.45 m/sec. While the amount of springback decreases as the loading speed increases, the effect due to the strain rate hardening of material, such as low carbon steel, becomes more dominant and is demonstrated in the analysis of dent resistance of a rectangular steel plate impulsively loaded

Pressure induced superconductivity in CaFe2_2As2_2

CaFe$_2$As$_2$ has been found to be exceptionally sensitive to the application of hydrostatic pressure and superconductivity has been found to exist in a narrow pressure region that appears to be at the interface between two different phase transitions. The pressure - temperature ($P - T$) phase diagram of CaFe$_2$As$_2$ reveals that this stoichiometric, highly ordered, compound can be easily tuned to reveal all the salient features associated with FeAs-based superconductivity without introducing any disorder. Whereas at ambient pressure CaFe$_2$As$_2$ does not superconduct for $T > 1.8$ K and manifests a first order structural phase transition near $T \approx 170$ K, the application of $\sim 5$ kbar hydrostatic pressure fully suppresses the resistive signature of the structural phase transition and instead superconductivity is detected for $T < 12$ K. For $P \ge 5.5$ kbar a different transition is detected, one associated with a clear reduction in resistivity and for $P > 8.6$ kbar superconductivity is no longer detected. This higher pressure transition temperature increases rapidly with increasing pressure, exceeding 300 K by $P \sim 17$ kbar. The low temperature, superconducting dome is centered around 5 kbar, extending down to 2.3 kbar and up to 8.6 kbar. This superconducting phase appears to exist when the low pressure transition is suppressed sufficiently, but before the high pressure transition has reduced the resistivity, and possibly the associated fluctuations, too dramatically

Comparison of Career Decision Difficulties Between Nursing Freshmen and Interns

Career selection is one of the most important decisions an individual makes in his life. High career expectation could result in career decision difficulties. This study aimed to compare and analyze the career decision difficulties between nursing freshmen and interns. This cross-sectional study involved 110 and 66 nursing freshmen and interns respectively (n=176) in two private nursing colleges. Career decision difficulties questionnaire was used in data collection. Descriptive statistic and independent sample t test were used in data analysis (α&lt;.05). Results showed that most respondents experienced moderate difficulties in both groups. Overall, there was no significant difference of career decision difficulty found between groups (p=.057), but indecisiveness, dysfunctional myths, lack of knowledge about the process of career decision making, lack of information, lack of information about occupations, lack of information about ways of obtaining additional information, and internal conflicts were significantly different between groups (all p&lt;α). Career decision difficulties occur similarly both in nursing freshmen and interns

The Best Predictor of Anxiety, Stress, and Depression Among Institutionalized Elderly

Anxiety, stress, and depression are the three most common negative emotional constructs found in the elderly. Evidences available worldwide about how psychological problem could be resulted in mental disorder, and there is significant difference in the context of living in the nursing home and in community setting. This study aimed to determine the best predictor of anxiety, stress, and depression in elderly living in the nursing home, useful for future modification and intervention development. This cross-sectional study involved 145 elderly in a private nursing home in Surabaya, Indonesia. HARS, SPST-20, and GDS were used in data collection. Linear regression and one way ANOVA tests were used in data analysis (α&lt;0.05). Results showed that mostly in old individuals, mild anxiety and stress, and undepressed state were found. Sensory problems and concentration difficulties were the best predictor of anxiety and stress respectively, which were accounted for 61.2% and 65.6% variances of anxiety and stress in nursing home residents respectively. Spirits, life energy, happiness, and feeling wonderful to be alive could not predict depression significantly. Feeling inferior to others is the best predictor of depression, which was accounted for 25.9% variance of depression in this population. Low self-esteem leads to depression in nursing home residents

Predictors of Post Prandial Glucose Level in Diabetic Elderly

Post prandial glucose (PPG) level describes the speed of glucose absorption after 2 hours of macronutrient consumption. By knowing this, we could get the big picture of insulin regulation function and macronutrient metabolism in our body. In elderly, age-related slower glucose metabolism leads to diabetes mellitus (DM) in older age. This study aimed to analyze the predictors of PPG level in diabetics elderly which consist of functional status, self-care activity, sleep quality, and stress level. Cross-sectional study design was applied in this study. There were 45 diabetic elderly participated by filling in study instruments. Pearson and Spearman Rank correlation test were used in data analysis (α&lt;.05). Results showed that most respondents were female elderly, 60-74 years old, had DM for 1-5 years with no family history, and only 33.33% respondents reported regular consumption of oral anti diabetes (OAD). Hypertension was found to be frequent comorbidity. Statistical analysis results showed that functional status, self-care activity, sleep quality, and stress level were not significantly correlated with PPG level in diabetic elderly (all p&gt;α), therefore these variables could not be PPG level predictors. Other factors may play a more important role in predicting PPG level in diabetic elderly

Spatial data stream multiplexing scheme for high-throughput WLANs

A novel scheme using spatial data stream multiplexing (SDSM) in the upcoming multiple-input multipleoutput (MIMO)-based IEEE 802.11n physical layer is proposed. It is shown that with SDSM, the same data rate can be achieved by using less number of transmit and receive antennas and therefore this scheme can reduce the number of antennas which results in reducing mutual coupling effects, hardware costs and implementation complexities. The maximum data rates that can be achieved using a 2 * 2 MIMO system is 270 Mbps and for a 4 * 4 MIMO system is 540 Mbps. The same data rates can be achieved using the SDSM technique which reduces the 2 * 2 MIMO system to 1 * 1 SISO system and the 4 * 4 MIMO system to a 2 * 2 MIMO system

Deep mantle structure and the postperovskite phase transition

Seismologists have known for many years that the lowermost mantle of the Earth is complex. Models based on observed seismic phases sampling this region include relatively sharp horizontal discontinuities with strong zones of anisotropy, nearly vertical contrasts in structure, and small pockets of ultralow velocity zones (ULVZs). This diversity of structures is beginning to be understood in terms of geodynamics and mineral physics, with dense partial melts causing the ULVZs and a postperovskite solid–solid phase transition producing regional layering, with the possibility of large-scale variations in chemistry. This strong heterogeneity has significant implications on heat transport out of core, the evolution of the magnetic field, and magnetic field polarity reversals

Adaptive fair channel allocation for QoS enhancement in IEEE 802.11 wireless LANs

The emerging widespread use of real-time multimedia applications over wireless networks makes the support of quality of service (QoS) a key problem. In this paper, we focus on QoS support mechanisms for IEEE 802.11 wireless ad-hoc networks. First, we review limitations of the upcoming IEEE 802.11e enhanced DCF (EDCF) and other enhanced MAC schemes that have been proposed to support QoS for 802.11 ad-hoc networks. Then, we describe a new scheme called adaptive fair EDCF that extends EDCF, by increasing the contention window during deferring periods when the channel is busy, and by using an adaptive fast backoff mechanism when the channel is idle. Our scheme computes an adaptive backoff threshold for each priority level by taking into account the channel load. The new scheme significantly improves the quality of multimedia applications. Moreover, it increases the overall throughput obtained both in medium and high load cases. Simulution results show that our new scheme outperforms EDCF and other enhanced schemes. Finally, we show that the adaptive fair EDCF scheme achieves a high degree of fairness among applications of the same priority level