Charlton Fire Department Resident Expectations: Survey and Analysis

The Town of Charlton is located in the heart of the Massachusetts with a resident population of just under 14,000 people. The Charlton Fire Department serves the town for needs related to fire fighting, fire prevention, burning permits and inspection services along with emergency medical services. The Department has requested the assistance of the Clark University COPACE Capstone students in creating and conducting survey in order to get a sense of what the resident of the town know about the fire department and to better gauge their expectations about what the department can provide for them. The survey was formulated in conjunction with the Fire Department and was conducted for a two-week period in April 2016. This report seeks to summarize and analyze the survey formulation process, the results of the survey and recommend best practices for the Charlton Fire Department in their resident engagement efforts in the future

Numerical and experimental investigation on self-synchronization of two eccentric rotors in the vibration system

In this paper, we study the coupling dynamic characteristic of a single mass vibration machine driven by two eccentric rotors rotating oppositely. According to the coordinate of rotor flux, we deduce the electromagnetic torque of an induction motor in the steady state operation. From three ways of numerical analysis, model simulation and experiment, we discuss the coupling dynamic characteristic by using the actual parameters of this vibration machine. The results show that when the synchronization condition is satisfied, not only the vibration synchronization transmission can be achieved, but also the synchronization motion of the two motors with different power supply frequencies also can be achieved. The phase of the bigger mass-radius product lags behind that of the smaller one, the phase of the bigger distance between the rotation center of eccentric rotor and the mass center of the vibration rigid body lags behind that of the smaller one, and the phase difference decreases with increasing the synchronization velocity. We present a new method that adjusting the power supply frequencies of the two motors to make the vibration system with different structure parameters carry out the 0 phase difference, and its feasibility is verified by experiment

Differential Responses of Net N Mineralization and Nitrification to Throughfall Reduction in a Castanopsis Hystrix Plantation in Southern China

Background Many regions in the world are experiencing changes in precipitation pattern, which likely impact soil nitrogen cycling and availability. However, we know little about how soil nitrogen processes respond to drought stress under climate change. Methods A continuous 5-year experiment of throughfall reduction treatment (TRT) was conducted in a Castanopsis hystrix plantation in subtropical China to assess how soil nitrogen processes responded to a change in precipitation. Net nitrogen transformation, soil properties, microbial biomass carbon (MBC) and nitrogen (MBN), and microbial community phospholipid fatty acids (PLFAs as bacteria, fungi and arbuscular mycorrhizal fungi (AMF)) were investigated in the wet and dry seasons over the period of the manipulation experiment. Results TRT had no significant effects on net ammonification rate (NAR) and nitrogen mineralization rate (NMR), and the unchanged NAR and NMR were mainly caused by the no change of soil nitrogen availability (i.e. NH4+-N, NO3−-N and dissolved organic nitrogen). However, TRT significantly increased net nitrification rate (NNR) in the wet season primarily due to the increase in NO3− concentration, and might be further caused by reduced NO3− leaching, denitrification or NO3−-N uptake in the TRT. Differently, TRT significantly decreased the NNR in the dry season, which might be linked to the limited SWC that resulted in greater microbial nitrate immobilization than gross nitrate mineralization. In addition, TRT significantly influenced the soil microbial community composition in 0–10 cm soil layer in the wet season, primarily due to the variations in NO3−-N, DOC and DON. Conclusions Precipitation reduction affected the NNR rather than NAR and NMR, and consequently, further affected soil N availability and N uptake by Castanopsis hystrix

Numerical and experimental investigation on self-synchronization of two eccentric rotors in the vibration system

In this paper, we study the coupling dynamic characteristic of a single mass vibration machine driven by two eccentric rotors rotating oppositely. According to the coordinate of rotor flux, we deduce the electromagnetic torque of an induction motor in the steady state operation. From three ways of numerical analysis, model simulation and experiment, we discuss the coupling dynamic characteristic by using the actual parameters of this vibration machine. The results show that when the synchronization condition is satisfied, not only the vibration synchronization transmission can be achieved, but also the synchronization motion of the two motors with different power supply frequencies also can be achieved. The phase of the bigger mass-radius product lags behind that of the smaller one, the phase of the bigger distance between the rotation center of eccentric rotor and the mass center of the vibration rigid body lags behind that of the smaller one, and the phase difference decreases with increasing the synchronization velocity. We present a new method that adjusting the power supply frequencies of the two motors to make the vibration system with different structure parameters carry out the 0 phase difference, and its feasibility is verified by experiment

Numerical and experimental investigation on self-synchronization of two eccentric rotors in the vibration system

In this paper, we study the coupling dynamic characteristic of a single mass vibration machine driven by two eccentric rotors rotating oppositely. According to the coordinate of rotor flux, we deduce the electromagnetic torque of an induction motor in the steady state operation. From three ways of numerical analysis, model simulation and experiment, we discuss the coupling dynamic characteristic by using the actual parameters of this vibration machine. The results show that when the synchronization condition is satisfied, not only the vibration synchronization transmission can be achieved, but also the synchronization motion of the two motors with different power supply frequencies also can be achieved. The phase of the bigger mass-radius product lags behind that of the smaller one, the phase of the bigger distance between the rotation center of eccentric rotor and the mass center of the vibration rigid body lags behind that of the smaller one, and the phase difference decreases with increasing the synchronization velocity. We present a new method that adjusting the power supply frequencies of the two motors to make the vibration system with different structure parameters carry out the 0 phase difference, and its feasibility is verified by experiment

Climate control of terrestrial carbon exchange across biomes and continents

Peer reviewe

Reconfigurable and tunable multi-tap bandpass microwave photonic filter based on a hybrid-gain-assisted multi-wavelength fiber ring laser

A reconfigurable and tunable multi-tap bandpass microwave photonic filter based on a hybrid-gain-assisted multi-wavelength fiber ring laser (HMFRL) is proposed and experimentally demonstrated. The HMFRL containing a hybrid gain medium and a high birefringence fiber loop mirror serves as the multiple taps generator for the microwave photonic filter. In order to realize a bandpass filter, the multiple taps are phase modulated, then the modulated signal is launched into a coil of dispersion compensating fiber to introduce different time delays for each tap. As a result, a bandpass response is obtained at the output of a high speeding photodetector. By adjusting the bias of the semiconductor optical amplifier from 344 to 450 mA, the number of multiple taps can be increased without optical signal-to-noise ratio degradation. Thus, a multi-tap bandpass microwave photonic filter with bandwidth reconfiguring from 449 to 274 MHz is achieved. In addition, by changing the length of polarization maintaining fiber in the high birefringence fiber loop mirror, the wavelength spacing of the multiple taps can be adjusted, making the bandpass microwave photonic filter’s free spectral range tunable

Floating sphere assay: A rapid qualitative method for microvolume analysis of gelation.

A huge, unprecedented demand for gelatin coupled with its implications on global sustainability has resulted in the need to discover novel proteins with gelling attributes for applications in the food industry. Currently used gelation assays require large sample volumes and thus the screening for novel gelling proteins is a formidable technical challenge. In this paper, we report the 'Floating Sphere Assay' which is a simple, economical, and miniaturized assay to detect minimum gelling concentration with volumes as low as 50 μl. Results from the Floating Sphere Assay are consistent with currently used methods for gelation tests and accurately estimate the Minimum Gelling Concentrations (MGCs) of gelatin, κ-carrageenan and gellan gum. The assay was also able to differentiate the strengths of strong and weak gellan gum gels prepared at pH 3.5 and pH 7.0 respectively. The Floating Sphere Assay can be utilized in high-throughput screens for gelling proteins and can accelerate the discovery of gelatin substitutes

Differential responses of net N mineralization and nitrification to throughfall reduction in a Castanopsis hystrix plantation in southern China

Abstract Background Many regions in the world are experiencing changes in precipitation pattern, which likely impact soil nitrogen cycling and availability. However, we know little about how soil nitrogen processes respond to drought stress under climate change. Methods A continuous 5-year experiment of throughfall reduction treatment (TRT) was conducted in a Castanopsis hystrix plantation in subtropical China to assess how soil nitrogen processes responded to a change in precipitation. Net nitrogen transformation, soil properties, microbial biomass carbon (MBC) and nitrogen (MBN), and microbial community phospholipid fatty acids (PLFAs as bacteria, fungi and arbuscular mycorrhizal fungi (AMF)) were investigated in the wet and dry seasons over the period of the manipulation experiment. Results TRT had no significant effects on net ammonification rate (NAR) and nitrogen mineralization rate (NMR), and the unchanged NAR and NMR were mainly caused by the no change of soil nitrogen availability (i.e. NH4 +-N, NO3 −-N and dissolved organic nitrogen). However, TRT significantly increased net nitrification rate (NNR) in the wet season primarily due to the increase in NO3 − concentration, and might be further caused by reduced NO3 − leaching, denitrification or NO3 −-N uptake in the TRT. Differently, TRT significantly decreased the NNR in the dry season, which might be linked to the limited SWC that resulted in greater microbial nitrate immobilization than gross nitrate mineralization. In addition, TRT significantly influenced the soil microbial community composition in 0–10 cm soil layer in the wet season, primarily due to the variations in NO3 −-N, DOC and DON. Conclusions Precipitation reduction affected the NNR rather than NAR and NMR, and consequently, further affected soil N availability and N uptake by Castanopsis hystrix

Polarization dependence of stimulated Brillouin scattering-based switchable microwave photonic filter

We propose and experimentally demonstrate a switchable microwave photonic filter based on polarization dependence of stimulated Brillouin scattering (SBS). The continuous optical wave from a tunable laser source is split into two branches. One branch serves as the SBS pump source and another branch serves as the signal source which are interactional to generate the SBS effect in the dispersion-shifted fiber. Only by adjusting the polarization direction of pump light and signal light, a frequency response switched between bandpass and notch filtering shape can be obtained