Semi-Empirical Methods For Electronic Properties Of Surface Adsorbed Molecules.

In the work described here, semi-empirical, theoretical tools have been developed to address one-electron properties of substrate/adsorbate systems. The tools are adaptations of the simple, Hückel π-electron theory and of the fast accurate-kinetic energy theory of F. Harris et al. (FAKE) to systems involving an infinite, mostly periodic substrate via a Green-function formalism. These tools are applied here to study graphene with vacancies and adsorbates, but can be generalized. In π theory, only a small subset of substrate basis states having odd reflection symmetry through the graphene layer are used to treat electrons near the Fermi level, to a very crude level of approximation. The substrate model Hamiltonian has been extended to contain second third and fourth nearest neighbor interactions. In the FAKE method, a semi-empirical tight-binding, charge self-consistent Hamiltonian is developed in which kinetic energy integrals are evaluated exactly and potential energy terms are extrapolated via a Müllikan formula using the overlaps. The methods are applied to anisolated atomic hydrogen adsorbate, and to vacancy and edge states on the graphene substrates. By comparing to experiments including scanning tunneling microscopy and to theoretical work including augmented plane wave (APW) and first principles density functional and other theoretic work, the theoretical tools developed here are seen to give good results and can in principle provide an efficient, potentially faster way of handling very large adsorbed molecules

Detailing provisions to control bar buckling in ductile RC walls

Bar buckling in ductile reinforced concrete (RC) walls is a commonly observed failure mode which limits their deformation capacity. To delay this undesirable failure mode in RC walls, most design codes emphasize on restricting the spacing of transverse reinforcement in the plastic hinges of RC walls. On the other hand, past research has shown that bar buckling in RC structures could span multiple tie spacings and the efficacy of transverse reinforcement to restrain bars against buckling is a function of the effective axial stiffness of transverse reinforcement in addition to the spacing of transverse reinforcement. To overcome these design limitations, a new mechanics-based design procedure to control bar buckling in ductile RC walls was recently proposed. In this paper, the newly developed guidelines for designing transverse reinforcement to control bar buckling in RC walls are summarized. Restrictions on both the axial stiffness of the tie legs and spacing of transverse reinforcement along the longitudinal reinforcing bars are proposed to confine bar buckling between the consecutive stirrups. Further, the average cyclic stress-strain response of reinforcing bars is utilized to limit compressive stress degradation in reinforcing bars until the design ductility demands are met

Design of Digital Solar Water Pump Using Microcontroller ATmega 32

This paper focuses on the application of solar energy along with microcontrollers to design and run a motor to pump water from various sources. The solar water pump is one of the applications or appliance that perform task with the use of solar radiation. The solar water pump consists of solar PV array, solar pump, inverter, AC water pumping device etc. Solar energy radiation is converted in electrical current or power source which is then used to run a pump and draw water directly from ground, wells, rivers, lakes etc. In this paper, the relationship between flow rate of the water and luminous intensity of the solar irradiance is studied and the data are linearly fitted to find out the correlation between these parameters. Also the study about efficiency of the solar powered water pump shows that the operation of this type of pumping system is quite efficient than other types of fossil fuel engines like diesel, petrol, kerosene etc. in long run. The use of Arduino Uno, flow sensor, LDR sensors in the solar powered water pump helps to analyze the relation between these parameters and know the conditions favorable for excess supply of water in short time efficiently. These solar powered devices are the future of clean and green future of this world. Thus it is not only necessary but also compulsory to enhance the usage of solar energy throughout the globe

Experimental validation of a low-damage rocking precast concrete cladding system

This paper presents experimental validation of an innovative precast concrete cladding panel system that can resist design level inter-story drifts through 'rocking' of panels without incurring any significant damage. Two precast panels are manufactured with four vertically-slotted steel-embeds, allowing the bolts connecting the panels to the structure to slide and the panels to rock up to an intended lateral drift demand. The panels are placed adjacent to each other with a 15 mm wide vertical joint in between them, interjected with sealant, on a single-story steel frame, and subjected to quasi-static in-plane drift cycles. The test results show the ability of the 'rocking' panels to accommodate large lateral drifts (up to 4% in this test) without any noticeable damage to the panels or their connections requiring repair. The only damage observed during the test was distortion and tear of the sealant at close to 2% drift levels

Effects of Lateral Ligament Sectioning on the Stability of the Ankle and Subtalar Joint

Patients with subtalar joint instability are often diagnosed with ankle instability. Only after a prolonged period of time in which a patient does not improve after treatment for ankle instability is subtalar joint instability considered. To develop a clinically relevant method to diagnose subtalar joint instability, the kinematics of the simulated unstable subtalar joint were examined. A 6 degree-of-freedom positioning and loading device was developed. Plantarflexion/dorsiflexion, inversion/eversion, and internal/external rotation were applied individually or as coupled motions along with an anterior/posterior drawer. Kinematic data were collected from sensors attached to the calcaneus, talus, and tibia by keeping all the ligaments intact, and by serially sectioning anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), cervical ligament, and talocalceneal interosseous ligament. Kinematic results were reported using Euler angles. The ATFL and CFL contributed talocrural instability, similar to previous studies. The interosseous ligament was the greatest contributor to subtalar joint stability. The hindfoot motion (calcaneus relative to tibia) showed significant increases in motion when the ankle and/or subtalar joint was made to be unstable. Therefore, it is difficult to diagnose subtalar joint instability on physical examination alone. (C) 2011 Orthopaedic Research Society

Derivation and application of performance group weighting factors for rapid seismic loss estimation

Despite most buildings confirming to life-safety requirements in modern seismic design codes, enormous financial losses are still incurring from many recent major seismic events around the globe. One tool to quantify and identify the source of these losses is seismic loss estimation, which considers losses arising from building damage, occupancy disruption (downtime) and death/injury. While significant progress had been made to simplify loss estimation procedures for easier applications, they are still not readily usable in everyday engineering design practice. One reason for this is due to insufficient information being readily available regarding the inevitable variations in the type and density of different structural and non-structural building components present in buildings of different occupancy types. This study aims to establish groups of building occupancy types based on similar initial cost ratio of the three key performance groups; structural components, non-structural drift-sensitive components, and non-structural accelerationsensitive components. This involved extracting component construction/installation costs from a New Zealand construction cost handbook for a range of different building occupancy types, summing the costs based on the three performance groups, then grouping the occupancy types based on similar structural and non-structural component costs. Weighting factors for each performance group, which represent the ratio of the performance group cost to the total cost, were then proposed for each building occupancy group. It should be noted that while the methodology adopted in this study can be used in other regions, the specific values and building occupancy groups proposed in this paper is specific to New Zealand application. A total of 79 different occupancy types were considered and grouped into four different building occupancy categories. Mean values of the performance group weighting factors for each occupancy category was computed and proposed. A case study demonstrating the application of the proposed weighting factors in rapid seismic loss estimation is provided. The results of this case study were compared against ones derived using more resource-intensive component-level seismic loss estimation calculations, where it was found that both approaches provided similar estimates. This showed that the simplified approach was not only easier and quicker to apply, but was also reasonably accurat

Damage avoidance design steel beam-column moment connection using high-force-to-volume dissipators

Existing welded steel moment frames are designed to tolerate substantial yielding and plastic rotation under earthquake loads. This sacrificial design approach can lead to permanent, and often irreparable damage when interstory drifts exceed 2%. The experimental seismic performance of a 50% full-scale damage avoidance designed structural steel beam-column connection is presented. The beam-column joint region consists of a top flange-hung beam connected to the column by an angle bracket. High-force-to-volume (HF2V) devices are attached from the column to the beam to provide joint rigidity and energy dissipation as the joint opens and closes. The HF2V devices are connected either below the beam flange or concealed above the beam's lower flange. Reversed cyclic lateral load tests are conducted with drift amplitudes up to 4%. No damage is observed in the principal beam and column structural elements. The need for stiff device connections to achieve optimal device performance is demonstrated, and potential design solutions presented. Stable hysteresis and repeatable energy dissipation for a large number of cycles up to the 4% drift level is observed. It is concluded that superior and repeatable energy dissipation without damage can be achieved for every dynamic motion cycle, in contrast to conventional sacrificially designed welded moment frame connections

A Global Collaboration to Develop and Pilot Test a Mobile Application to Improve Cancer Pain Management in Nepal

INTRODUCTION: Quality palliative care, which prioritizes comfort and symptom control, can reduce global suffering from non-communicable diseases, such as cancer. To address this need, the Nepalese Association of Palliative Care (NAPCare) created pain management guidelines (PMG) to support healthcare providers in assessing and treating serious pain. The NAPCare PMG are grounded in World Health Organization best practices but adapted for the cultural and resource context of Nepal. Wider adoption of the NAPCare PMG has been limited due to distribution of the guidelines as paper booklets. METHODS: Building on a long-standing partnership between clinicians and researchers in the US and Nepal, the NAPCare PMG mobile application (“app”) was collaboratively designed. Healthcare providers in Nepal were recruited to pilot test the app using patient case studies. Then, participants completed a Qualtrics survey to evaluate the app which included the System Usability Scale (SUS) and selected items from the Mobile App Rating Scale (MARS). Descriptive and summary statistics were calculated and compared across institutions and roles. Regression analyses to explore relationships (α = 0.05) between selected demographic variables and SUS and MARS scores were also conducted. RESULTS: Ninety eight healthcare providers (n = 98) pilot tested the NAPCare PMG app. Overall, across institutions and roles, the app received an SUS score of 76.0 (a score > 68 is considered above average) and a MARS score of 4.10 (on a scale of 1 = poor, 5 = excellent). 89.8% (n = 88) “agreed” or “strongly agreed” that the app will help them better manage cancer pain. Age, years of experience, and training in palliative care were significant in predicting SUS scores (p-values, 0.0124, 0.0371, and 0.0189, respectively); institution was significant in predicting MARS scores (p = 0.0030). CONCLUSION: The NAPCare PMG mobile app was well-received, and participants rated it highly on both the SUS and MARS. Regression analyses suggest end-user variables important to consider in designing and evaluating mobile apps in lower resourced settings. Our app design and pilot testing process illustrate the benefits of cross global collaborations to build research capacity and generate knowledge within the local context

Critical success factor bagi program keusahawanan di jabatan perdagangan politeknik

Konsep Critical Success Factor berkait rapat mengenai pengurusan dalam mencapai misi dan matlamat perniagaan dalam sesebuah organisasi. Oleh itu, kajian ini adalah bertujuan untuk mengkaji empat elemen Critical Success Factor di Jabatan Perdagangan Politeknik seterusnya melihat kecenderungan pelajar untuk melibatkan diri dalam bidang keusahawanan. Kajian jenis kuantitatif ini telah dibuat ke atas pensyarah di Jabatan Perdagangan Politeknik bagi zon Utara. Seramai 190 sampel kajian yang terlibat dalam penyelidikan ini melalui pengedaran borang kaji selidik. Antara enam buah politeknik di zon Utara yang terlibat dalam penyelidikkan ini adalah Politeknik Politeknik Tunku Syed Sirajuddin, Perlis, Politeknik Sultan Abdul Halim Muazzam Shah, Kedah, Politeknik Tunku Sultanah Bahiyah, Kedah, Politeknik Seberang Perai, Pulau Pinang, Politeknik Ungku Omar, Perak dan Politeknik Sultan Azlan Shah, Perak. Data yang diperolehi dianalisis mendapati nilai skor min bagi ketiga-tiga persoalan kajian iaitu, mengenalpasti elemen Critical Success Factor yang digunakan, cabaran dalam usaha melaksanakan elemen Critical Success Factor dan mengenalpasti tahap kecenderungan pelajar untuk melibatkan diri dalam bidang keusahawanan adalah tinggi. Manakala bagi persoalan kajian keempat iaitu mencari hubungan korelasi Pearson antara elemen Critical Suceess Factor dengan kecenderungan pelajar untuk melibatkan diri dalam bidang keusahawanan adalah berada pada tahap lemah, sekaligus menunjukkan Ho tidak diterima. Kesimpulannya, elemen Critical Success Factor ini memainkan peranan dalam pembentukkan organisasi yang berkesan supaya pembentukan matlamat dan objektif tercapa