Fundraising and Optimal Policy Rules

This paper develops a simple spatial model of fundraising, in which charities select a target population to solicit donations. First, we show that in a competitive charity market without any intervention, the number of charities in the market and/or the overall net funds raised by charities may be sub-optimal. Next, we analyze whether a social planner can prevent such shortcomings and show that a regulatory mechanism can be designed to achieve socially desirable outcomes. In contrast to the previous literature, our model does not necessarily produce monopoly as the optimal market structure. We show that if fixed costs associated with establishing charities are sufficiently low, then the optimal market structure is not a monopoly. Given the importance of the trade-o¤ between the volume and variety of charitable services, we argue that this result may be of particular interest to policy makers

Finitely Many Dirac-Delta Interactions on Riemannian Manifolds

This work is intended as an attempt to study the non-perturbative renormalization of bound state problem of finitely many Dirac-delta interactions on Riemannian manifolds, S^2, H^2 and H^3. We formulate the problem in terms of a finite dimensional matrix, called the characteristic matrix. The bound state energies can be found from the characteristic equation. The characteristic matrix can be found after a regularization and renormalization by using a sharp cut-off in the eigenvalue spectrum of the Laplacian, as it is done in the flat space, or using the heat kernel method. These two approaches are equivalent in the case of compact manifolds. The heat kernel method has a general advantage to find lower bounds on the spectrum even for compact manifolds as shown in the case of S^2. The heat kernels for H^2 and H^3 are known explicitly, thus we can calculate the characteristic matrix. Using the result, we give lower bound estimates of the discrete spectrum.Comment: To be published in JM

How Responsive are Charitable Donors to Requests to Give?

People tend to contribute to a charity only when they are asked to. Although this so-called 'power of asking' is a well-known technique among fundraisers, the existing literature does not pay much attention to the role of donation requests in charitable giving. We estimate the causal effects of charitable solicitations on both the propensity to give and the amount of charitable contributions using a unique data set, which was designed to measure the giving behavior in the United States. In order to address the endogeneity of the donation requests due to non-random solicitation of charitable donors, we link this data set to IRS data on charitable organizations and the 2000 Census and propose identifying instruments. After controlling for the endogeneity, we find that people are both more likely to contribute to a charity and also donate more when they are asked to. This effect is robust under different specifications and with different sets of instruments and is much larger compared with the estimates of univariate models. Furthermore, we argue that some identifiable characteristics of individuals are associated with the higher probability of being solicited. In particular, we find some evidence that income, age, education, and race play significant roles in explaining the selection of potential charitable donors.charitable contributions, charitable solicitations, non-profit organizations

Analysis of accuracy of sensor readings and locations in gas monitoring networks in underground coal mines: Ttk kozlu colliery [Yeralti kömür ocaklarinda gaz izleme aglari sensör ölçümlerinin ve konumlarinin dogrulugunun analizi: Ttk kozlu müessesesi]

Harmful gas concentrations in underground lignite and hardcoal mines in Turkey, as in the world, are monitored via sensors and evaluations can be made for the mine. In this context, this study covers the preliminary results of a study initiated to determine the accuracy of the sensors and their locations in the mines of the Kozlu Colliery of Turkish Hardcoal Enterprise (TTK). In the study, methane (CH4) concentrations and air velocity measurements were manually done in certain locations in the underground and compared to sensor readings. Moreover, in order to observe the changes in the air density, relative humidity, wet and dry bulb temperatures and barometric pressures were measured. The results of the study showed that air velocity values range from 1.232 to 1.312 kg/m3, methane sensors recorded values 5 to 10% more than manual readings and manual readings for air velocity were 50%, on an average, more than sensor readings

Effects of starvation and re-alimentation periods on growth performance and hyperphagic response of Sparus aurata

[No abstract available

Determination of the gas content of buyuk seam of ttk armutcuk colliery by direct measurement method [Ttk armutçuk müessesesi büyük damar gaz içeriginin dogrudan ölçme yöntemiyle belirlenmesi]

The goal of this study is to determine the gas content of Buyuk seam at TTK's Armutcuk Colliery by applying one of the direct methods. The direct gas measurement methods used to determine the gas contents of the coal seams were studied and Australian Standard was selected as suitable. In this study, using the cuttings obtained from 12 core drillings done in a virgin section of Buyuk Seam (-540 level) of Armutcuk Colliery of TTK, where a panel development is readily conducted gas content of the samples were determined according to "fast and slow desorption" procedures. The results obtained from the study revealed that gas contents of coal samples are in the range of 8,5-14,7 m3/t, and 9,0-17.4 m3/t by fast and slow desorption method, respectively. Arithmetic averages of the gas contents at this part of the Buyuk seam shows that the gas content can be accepted as 10-12 m3/t. Also, the initial desorption of a sample is accepted first as linear then as logarithmic and only slight differences have been observed between two approaches regarding the total gas contents. The Australian Standard method can easily be used on borehole cuttings in TTK collieries adapting the instrumentation achieved and experience gained in this study

Size-Related Evaluation of Unburned Carbon

The unburned carbon (UBC) content of ash from coal-fired thermal power stations and plants that use massive amount of coal can sometimes be 6-7% or more; this simply means loss of carbon and decrease in efficiency. Carbon loss not only causes a decrease in efficiency but is also an economical issue. Decreasing the carbon content would provide the usage of ash from thermal power stations as cement additives. Many factors cause low combustion efficiency and a high amount of UBC. In the course of this study, fly ash and bottom ash were divided into size fractions and accumulation of UBC at coarser size fractions was observed. In this study, a ground coal sample from a mill was sieved, and the accumulation of UBC at coarser size fractions was associated to a lack of grinding of pulverized coal. Ground coal has a size distribution where 54.45% was below 75 µm, and 45.55% was still over this critical size. A significant amount (35.48%) of the UBC accumulated in the size fraction over 75 µm in fly ash, whereas almost 70% accumulated in the size fraction over 0.5 mm in bottom ash. Coal and ash samples were observed under a microscope to deduce origins of UBC. © 2016 Taylor & Francis

Enrichment of 8-125 mm Colemanite Ores via NIR/CCD Optical Sorter

In this study, 8-125 mm Simav Ana Damar (SAD), Simav Tali Damar (STD) and Tülü Sarı (TS) raw colemanite ores which extracted together with the minerals such as clay, tuff, limestone from the quarries of Bigadiç Boron Works Management of Eti Maden enriched by optical sorters used with near-infrared (NIR) and visible light (CCD) sources. In these works, the ore passing through the crushing, sieving and washing processes was fed to two optical sorters of 8-25 mm and 25-125 mm grain sizes and the 3.90-9.10 units enrichment was obtained in the ores fed at 22.10-39.30% B2O3 content. After enrichment made with over 93% yield, waste was found to be in the range of 2.20-11.10% B2O3 grade

Immunoexpression of p38 Mitogen-Activated Proteinkinase in Patients with Aggressive and Chronic Periodontitis

The influence of p38 mitogen-activated proteinkinase (MAPK) expression in the development and progression of periodontal disease is currently under investigation. The aim of the present study is to investigate whether the p38 MAPK expression in gingival tissues correlates with IL-1β levels in gingival crevicular fluid (GCF). Twenty patients with generalized aggressive periodontitis (GAgP), 15 patients with generalized chronic periodontitis (GCP) and 10 healthy subjects (H) were enrolled in the study. Clinical data, gingival tissue biopsies and GCF samples were collected. The expression of p38 was investigated by immunohistochemistry. The levels of IL-1β in GCF were measured using ELISA. Mean clinical parameters and GCF volumes were statistically higher in patients with GAgP and GCP compared to H subjects. Higher levels of IL-1β were found in both periodontitis groups. The p38 expression was significantly increased in inflamed gingival tissues. There were no statistically significant differences in levels of IL-1β and p38 expression between subjects with GAgP and GCP. Our data support the hypothesis that MAPK signaling pathway is an additional player in the pathogenesis of periodontitis. This is the first report to evaluate the involvement of p38 MAPK in patients with GAgP and GCP which might be, in part, considered of value in understanding disease mechanisms