Security Constrained Multi-Stage Transmission Expansion Planning Considering a Continuously Variable Series Reactor

This paper introduces a Continuously Variable Series Reactor (CVSR) to the transmission expansion planning (TEP) problem. The CVSR is a FACTS-like device which has the capability of controlling the overall impedance of the transmission line. However, the cost of the CVSR is about one tenth of a similar rated FACTS device which potentially allows large numbers of devices to be installed. The multi-stage TEP with the CVSR considering the $N-1$ security constraints is formulated as a mixed integer linear programming model. The nonlinear part of the power flow introduced by the variable reactance is linearized by a reformulation technique. To reduce the computational burden for a practical large scale system, a decomposition approach is proposed. The detailed simulation results on the IEEE 24-bus and a more practical Polish 2383-bus system demonstrate the effectiveness of the approach. Moreover, the appropriately allocated CVSRs add flexibility to the TEP problem and allow reduced planning costs. Although the proposed decomposition approach cannot guarantee global optimality, a high level picture of how the network can be planned reliably and economically considering CVSR is achieved.Comment: Accepted by IEEE Transactions on Power System

Iterative approach to arbitrary nonlinear optical response functions of graphene

Two-dimensional materials constitute an exciting platform for nonlinear optics with large nonlinearities that are tunable by gating. Hence, gate-tunable harmonic generation and intensity-dependent refraction have been observed in e.g. graphene and transition-metal dichalcogenides, whose electronic structures are accurately modelled by the (massive) Dirac equation. We exploit on the simplicity of this model and demonstrate here that arbitrary nonlinear response functions follow from a simple iterative approach. The power of this approach is illustrated by analytical expressions for harmonic generation and intensity-dependent refraction, both computed up to ninth order in the pump field. Moreover, the results allow for arbitrary band gaps and gating potentials. As illustrative applications, we consider (i) gate-dependence of third- and fifth-harmonic generation in gapped and gapless graphene, (ii) intensity-dependent refractive index of graphene up to ninth order, and (iii) intensity-dependence of high-harmonic generation.Comment: 6 pages, 5 figures. Supplemental material: 6 pages, 2 figure

Технички решенија за зголемување на безбедноста и сигурноста при експлоатација на тракторите во јавниот сообраќај

Во трудот се прикажани техничките превентивни мерки со цел спречување и намалување на несреќите со трактори во земјоделското производство во Република Македонија. Според резултатите од истражувањата во Република Македонија во периодот од 2008 до 2012 година во сообраќајнте несреќи со трактори вкупно загинале 47 лица, 168 се тешко повредени и 604 лица се добиле со лесни повреди. Со цел спречување на бројот на несреќи со трактори и намалување на бројот на повредени лица во земјоделското производство треба доследно да се применуваат техничките мерки за зголемување на безбедноста и сигурноста при работа со земјоделските машини

Consequences of tractor accidents in the agriculture in Republic of Macedonia

In this paper are the results from the research of the consequences of tractor accidents in the agriculture in Republic of Macedonia. During the research from 1999 till 2003, 610 people have been injured in Republic of Macedonia in agricultural production, and the tractors have been the main reason. 544 people have been injured in tractor traffic accidents and 66 have been injured during tractor operating in agricultural condition. From the total number, 101 people have died during this period of time. 57 people have died in tractor traffic accidents and the rest of 44 people during tractor operating in agricultural condition. During the research, 172 people have been registered with hard injuries. 151 people have been injured in tractor traffic accidents and 21 during tractor operating in agricultural condition. Light injuries are also part of injuries that happen during tractor operating. During this research another 337 people have been registered with light injuries. The main causes of tractor accidents in the agriculture in Republic of Macedonia are: inattention of the tractor operator, improper speed according to the signs and road conditions, alcohol and malfunctions of the vehicle

The Therapeutic Effects of Lithium in Affective Disorders

Objective The main objective of this research was to explore the psychopathological aspects of affective disorder and the clinical effects of pharmacological treatment with lithium. Materials and Methods: The study involved 40 patientsts (26 females, 14 males) with an average age 45,5 years, hospitalized in the Psychiatric Hospital in Skopje and the Department of Psychiatry of Clinical Hospital in Tetovo, with a clinical diagnosis of affective disorder. The diagnosis of affective disorder is set against the classification DSM-IV (Diagnostic and Statistical Manuel of Mental Disorder). All subjects were under pharmacological treatment with lithium carbonats whose dose depends of the clinical subentitet, the beginning and duration of the disorder. Clinical-laboratory examinations included: history and clinical status, determination of serum lithium concentration. The serum lithium concentrations were measured by Ion-Selective Electrode (ISE) with the COBAS/INTEGRA 700 analyzer. Results: The results of the research show us that patient with acute phase of mania had higher concentration of lithium in serum compared with patients with bipolar affective psychosis. Also the patients who received combination theraoy (lithium/neuroleptic or antidepressant) mean values of lithium in serum range 1,89 mmol/L compared to patients who only used lithium whose mean values are 0,82 mmol/L. Pearson correlation between two groups was significantly significant at the level of 0,01. Conclusions: With the regular and continued use of lithium in affective disorders and good co-operation with the patient during the therapy could be reduced the relapses of the disease and improved the quality of life of the person. Key words: affective dosprder, lithium therapy, quality of lif