ANALISIS NERACA AIR SUNGAI TENDEKI DI TITIK BENDUNG TENDEKI KOTA BITUNG

Bendung Tendeki memanfaatkan air dari Sungai Tendeki untuk dikelola menjadi air minum oleh PDAM. Berdasarkan hal tersebut, maka diperlukan studi mengenai analisis neraca air untuk melihat keseimbangan antara ketersediaan dan kebutuhan air di DAS Tendeki.Ketersediaan air DAS Tendeki dihitung menggunakan debit andalan dengan pencatatan data debit terukur selama 10 tahun yang selanjutnya menghitung debit andalan Q90% sebagai ketersediaan air dan Q95% sesuai  Peraturan Pemerintah untuk pemeliharaan sungai. Kebutuhan air yang dihitung adalah kebutuhan pengambilan air IPA-SPAM PDAM dan kebutuhan pemeliharaan sungai atau Q95%. Analisis neraca air dilakukan dengan membandingkan ketersediaan air dengan kebutuhan air total di DAS Tendeki.Hasil analisis menunjukkan bahwa kebutuhan air minum dan kebutuhan pemeliharaan sungai Q95% tidak terpenuhi karena debit yang besar sehingga ketersediaan air tidak mencukupi. Ketersediaan air Q90% masih mencukupi untuk memenuhi kebutuhan air minum PDAM. Kata Kunci : Sungai Tendeki, DAS Tendeki, Debit Andalan, Neraca Ai

Perceived Attributes of Diffusion of Innovation Theory as a Theoretical Framework for understanding the Non-Use of Digital Library Services

Rogers’s diffusion of innovation theory is one theoretical approach to understand how members of a social system can adopt an innovation. Certain attributes of the innovation itself may facilitate its adoption. This paper highlights the necessity of designing a Digital Library Service (DLS) in conformity with the attributes of Innovation. These attributes are: relative advantage, compatibility, complexity, trialability and observability. It further discussed previous studies that have used the theory of perceived attribute of innovation to conduct research on acceptance and rejection of an innovation in different fields and concluded that Digital Library Service designers who adopts the theory of the perceived attributes of innovation will understand why there is low or non-use of these services and help them in designing DLS that can easily be adopted by potential users

Electrodynamic Radiation Reaction and General Relativity

We argue that the well-known problem of the instabilities associated with the self-forces (radiation reaction forces) in classical electrodynamics are possibly stabilized by the introduction of gravitational forces via general relativity

Dynamics of Fermat potentials in non-perturbative gravitational lensing

We present a framework, based on the null-surface formulation of general relativity, for discussing the dynamics of Fermat potentials for gravitational lensing in a generic situation without approximations of any kind. Additionally, we derive two lens equations: one for the case of thick compact lenses and the other one for lensing by gravitational waves. These equations in principle generalize the astrophysical scheme for lensing by removing the thin-lens approximation while retaining the weak fields.Comment: Accepted for publication in Phys. Rev.

Fetal Environment and Schizophrenia

Schizophrenia and related disorders are adult-onset illnesses with no definitively established risk factors. Several studies report that exposures to infection and nutritional deprivation during early development may elevate the risk of later developing schizophrenia, specifically during the prenatal period. Preliminary evidence implicates lead exposure as well, suggesting that chemical exposures during early development may constitute a new class of risk factors for schizophrenia that has not been adequately investigated. Exposure to lead is given as an example of a chemical agent for which some effects have been described throughout the life course on both general neurodevelopmental outcomes and now on a specific psychiatric diagnosis. Findings from prospectively collected birth cohorts are offered as examples of both innovations in methodology and opportunities for future generations of investigators

Phase-Space Metric for Non-Hamiltonian Systems

We consider an invariant skew-symmetric phase-space metric for non-Hamiltonian systems. We say that the metric is an invariant if the metric tensor field is an integral of motion. We derive the time-dependent skew-symmetric phase-space metric that satisfies the Jacobi identity. The example of non-Hamiltonian systems with linear friction term is considered.Comment: 12 page

Videographic Analysis of Blink Dynamics following Upper Eyelid Blepharoplasty and Its Association with Dry Eye

Background: This study was undertaken to characterize the effects of upper eyelid blepharoplasty on blink dynamics and to evaluate the hypothesis that changes in blink dynamics following blepharoplasty are associated with postoperative dry eye. // Methods: The voluntary blink of 14 eyes of 7 patients with dermatochalasis undergoing upper eyelid blepharoplasty was recorded with a high-speed camera preoperatively and 6–8 months postoperatively, alongside a group of 11 controls. The images were analyzed for palpebral aperture, blink duration, and maximum velocity during opening and closing phases. Patients undergoing blepharoplasty were assessed for dry eye symptoms pre- and postoperatively at 6–8 months using the ocular surface disease index score. // Results: Despite intraoperative orbicularis oculi resection, there was no significant compromise of blink duration or maximum velocity of eyelid opening or closure post-blepharoplasty. Postoperatively, patients had an increase in palpebral aperture compared with both preoperatively (8.71 versus 7.85mm; P = 0.013) and control groups (8.71 versus 7.87mm; P = 0.04). Postoperatively at 6–8 months, there was an increase in dry eye symptoms in 6 of 7 patients compared with preoperatively (ocular surface disease index, 16.6 versus 12.5; P < 0.05). There was no positive correlation between the increase in palpebral aperture and the increase in dry eye symptoms (r = –0.4; P = 0.30). // Conclusions: Using modern videographic technology, this study demonstrates that upper eyelid blepharoplasty results in an increase in resting palpebral aperture but has no effect on dynamic blink parameters. Changes in palpebral aperture or blink dynamics are unlikely to be the cause of dry eye syndrome following blepharoplasty

Image distortion in non perturbative gravitational lensing

We introduce the idea of {\it shape parameters} to describe the shape of the pencil of rays connecting an observer with a source lying on his past lightcone. On the basis of these shape parameters, we discuss a setting of image distortion in a generic (exact) spacetime, in the form of three {\it distortion parameters}. The fundamental tool in our discussion is the use of geodesic deviation fields along a null geodesic to study how source shapes are propagated and distorted on the path to an observer. We illustrate this non-perturbative treatment of image distortion in the case of lensing by a Schwarzschild black hole. We conclude by showing that there is a non-perturbative generalization of the use of Fermat's principle in lensing in the thin-lens approximation.Comment: 22 pages, 6 figures, to appear in Phys. Rev. D (January 2001

Semiclassical calculation of the vibrational echo

The infrared echo measurement probes the time scales of the molecular motions that couple to a vibrational transition. Computation of the echo observable within rigorous quantum mechanics is problematic for systems with many degrees of freedom, motivating the development of semiclassical approximations to the nonlinear optical response. We present a semiclassical approximation to the echo observable, based on the Herman-Kluk propagator. This calculation requires averaging over a quantity generated by two pairs of classical trajectories and associated stability matrices, connected by a pair of phase-space jumps. Quantum, classical, and semiclassical echo calculations are compared for a thermal ensemble of noninteracting anharmonic oscillators. The semiclassical approach uses input from classical mechanics to reproduce the significant features of a complete, quantum mechanical calculation of the nonlinear response