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Author: admin, 03.09.2015. Category: Organic Fertilizer

2.1The Licensed Material may not be used in any final materials distributed inside of your company or any materials distributed outside of your company or to the public, including, but not limited to, advertising and marketing materials or in any online or other electronic distribution system (except that you may transmit comps digitally or electronically to your clients for their review) and may not be distributed, sublicensed or made available for use or distribution separately or individually and no rights may be granted to the Licensed Material. 2.2One copy of the Licensed Material may be made for backup purposes only but may only be used if the original Licensed Material becomes defective, destroyed or otherwise irretrievably lost. Many of the hats we tested have mesh ventilation on the sides which decrease the hats UPF rating, but only by a small amount.
If you get a hat that doesn't completely cover your head and shoulders, make sure you wear sunscreen on your exposed skin so you don't get burned. Wearing a sun hat on a hot day can cool you down, but it can also heat you up if it doesn't breathe very well. A very important thing to decide before buying a sun hat is what activity you are going to be wearing it for.
A good sun hat will last you a lifetime, and give you many reasons to tell your friends of adventures you've had with it. About the AuthorDevin Chance is an avid outdoor enthusiast whose passions include rock climbing, skiing, and backpacking in the sierras.
A pioneer in the natural foods movement, Barbara’s was founded in 1971 by a 17-year old girl who was passionate about creating great-tasting food from simple, wholesome ingredients.
Barbara’s wholesome products means we choose high quality ingredients to provide optimal nutrition and taste. Join our community to learn more about Adopt-a-Puffin, watch our puffin cam, or even play a few games everyone can enjoy! Our Commitment to you doesn’t stop at our 100% recycled paperboard cereal cartons or our work with Project Puffin. Working Mother Magazine names Barbara’s Organic Snackimals Cereal as top 10 Healthy Convenience Breakfasts for Little Ones!
One way to increase the thermal efficiency of vehicle diesel engines is to recover waste heat by using an organic Rankine cycle (ORC) system. Figure 1 shows the MAP of the variation of available exhaust energy rate in the whole operating range of the engine. AcknowledgmentsThis work was sponsored by the National Natural Science Foundation of China (Grant No.
Except as specifically provided in this Agreement, the Licensed Material may not be shared or copied for example by including it in a disc library, image storage jukebox, network configuration or other similar arrangement. We took the five most important things to consider when buying a sun hat, and listed them in order of importance. It's better to put sunscreen on the parts that you think are protected, too, because sometimes when you turn your head you expose unprotected skin to harmful UV radiation. Breathable fabrics are used in most sun hats and will not overheat you unless you are doing physical activity.
If you are going to wear it climbing, then you might want one with a smaller brim so that when you look up the climb the hat doesn't hit your back and fall off. A bad fitting hat can either give you endless headaches if its too tight, or if its too big will feel loose and unstable. It will become more of a companion than just a hat and will make all of your friends jealous.
When buying a sun hat remember that a white one, although it may be the most effective, will get dirty and stained.
So before you buy a sun hat make sure you don't look like a total fool wearing it, unless of course you just don't care. He recently moved to South Lake Tahoe to pursue those passions and to attend a local college. At Barbara’s, we believe that life is delicious – and is worth taking a bite out of every day!
Barbara’s is committed to working with the non-GMO project and providing you with gluten free and vegan options. Tests were conducted to study the running performances of diesel engines in the whole operating range. IntroductionInternal combustion (IC) engines consume considerable amounts of petroleum resources. 51376011); Scientific Research Key Program of Beijing Municipal Commission of Education (Grant No. Once you license a royalty-free product, you may use it multiple times for multiple projects without paying additional fees.
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UPF ratings are a rating system that measures the amount of UV radiation admitted through fabrics. If you are going to wear it running then get a really lightweight hat that breathes well and doesn't fly off in the wind. So before you buy a sun hat, measure your head following the specific company sizing guidelines. So we suggest a hat that is easily washable or just a little bit darker so the stains don't show as much. Before the purchase see if you can get another opinion; sometimes what looks good to you in the mirror might actually just be your wild imagination. Devin plans on transferring to the University of California Davis, where he will receive his degree in economics. The law of variation of the exhaust energy rate under various engine operating conditions was also analyzed. The figure shows that the power output and available exhaust energy rate increase gradually with increasing engine speed and torque.
Description of the Mixed Working FluidsThe variation of the mass fraction of the components leads to the variation of the proprieties of the mixed working fluids, including critical parameters and environmentally friendly properties. The Licensed Material may only be used in materials for personal, noncommercial use and test or sample use, including comps and layouts.
If Licensed Material featuring a person is used (i) in a manner that implies endorsement, use of or a connection to a product or service by that model; or (ii) in connection with a potentially unflattering or controversial subject, you must print a statement that indicates that the person is a model and is used for illustrative purposes only.


Create your slideshowBy using the code above and embedding this image, you consent to Getty Images' Terms of Use. A UPF rating of 30+ blocks about 96 percent of UV radiation, while a UPF rating of 50+ blocks about 99 percent. However in the mean time his main goal is to have fun, and enjoy the mountain life while he still can. A diesel engine-ORC combined system was designed, and relevant evaluation indexes proposed. Most of the energy released from the fuel combustion in the cylinder is removed by the exhaust and cooling medium, thus wasting fuel resources, increasing costs and aggravating environmental problems [1]. The variation of the running performances of the combined system under various engine operating conditions was investigated. Recovering and utilizing waste heat is an effective way to increase the thermal efficiency and decrease fuel consumption and pollutant discharge [2].Organic Rankine cycle (ORC) systems are used to convert heat into power, allowing the utilization of medium and low temperature waste heat [3–4]. Therefore, the operating parameters of the ORC system should be regulated on the basis of the exhaust energy rate. In this study, we selected dry working fluid R245fa and wet working fluid R152a as components of the mixed working fluids, and six kinds of mixed working fluids with different component mass fractions were then created.
Subsequently, the efficient recovery of exhaust energy under various engine operating conditions can be achieved. The effects of the six kinds of mixed working fluids on the running performances of the combined system were investigated. The effects of mixed working fluids with different compositions on the running performances of the combined system were revealed.
Table 4 presents the property parameters of the six kinds of working fluid mixtures.Figure 4 shows the T-s diagram of the six kinds of mixed working fluids.
Results show that the running performances of the combined system can be improved effectively when mass fraction R152a in the mixed working fluid is high and the engine operates with high power.
Description of the ORC SystemA simple ORC system was established to recover the exhaust energy of the diesel engine. The graph shows that the decrease of the mass fraction of R152a causes the mixed working fluids to change from wet fluids to dry fluids and increases the critical temperature gradually, M4 approximates to the isentropic working fluid. To heat the working fluids, exhaust heat was used as the high temperature heat source of the ORC system. Figure 5 shows the glide temperature of the six kinds of mixed working fluids under different evaporating pressures. Several scholars have considered the use of ORC systems to recover engine waste heat [11–14]. Figure 2 shows the diesel engine-ORC combined system (henceforth “combined system”), which mainly includes the diesel engine, evaporator, expander, condenser, reservoir, and pump. The glide temperatures of the six kinds of mixed working fluids decrease gradually with increasing evaporating pressure.
Flow meters 1 and 2 were used to measure the liquid flux rate and gaseous flux rate of the working fluids, respectively.
Regardless of the evaporating pressure, the decrease of the mass fraction of R152a causes glide temperature to first increase and then decrease, and M4 reaches the maximum value. Temperature and pressure sensors were used to monitor the temperature and pressure of each state point in the system, respectively.Figure 3 shows the T-s diagram of the ORC system. Process 1–2 is the actual pressurization process wherein the working fluid is pressurized in a high pressure liquid state by the pump. Higher thermal efficiency corresponds to higher power output with respect to absorbing identical heat. Process 2–3 is the isobaric endothermic process wherein the working fluid turns into gas with high temperature and high pressure after absorbing heat from the exhaust. Figure 6 shows the variation of the thermal efficiency of the six kinds of mixed working fluids at different evaporating pressures.
Process a–b is the temperature glide process of the working fluids; the temperature difference between Points a and b is the glide temperature in the evaporating process of the working fluid. The decrease in mass fraction of the R152a in the mixed working fluids gradually decreases the thermal efficiency of the ORC system. The thermal efficiency of the ORC system initially increases and then decreases with increasing evaporating pressure. Thermal efficiency hits its maximum value (12.65%) when the evaporating pressure reaches 2 MPa.
In conclusion, the ORC system can effectively recover the waste heat, and then increase the thermal efficiency of the engine.The organic working fluids act as the working medium of the ORC system.
Equation (13) shows that the thermal efficiency depends primarily on the enthalpy value of some state points in the ORC system.
Under different working conditions, the selection of working fluid has an effect on the running performances of the ORC system [19–20].
The enthalpy value of the related sate point is determined mainly by the component performance and the physical properties of the working fluid itself.
Table 5 shows the enthalpy value of the related state points for the six kinds of mixed working fluids when evaporating pressure reaches 2 MPa. The decrease of the mass fraction of R152a in the mixed working fluids gradually increases the enthalpy values of State Points 1 and 2, while the amplitude of variation is relatively lower.
The decrease of the mass fraction of R152a in the mixed working fluids gradually decreases the enthalpy values of State Points 3 and 4, while the amplitude of variation is relatively higher. Therefore, according to Equation (13) and the enthalpy value of the related state points in Table 5, the variation of the thermal efficiency of the ORC system can be drawn as in Figure 6.Figure 7 shows the MAPs of the net power output of the six kinds of mixed working fluids under various engine operating conditions. The zeotropic mixture has a character of “temperature slip”, which can benefit the heat transfer between cold and hot fluids, thus reducing the irreversible loss caused by the heat transfer temperature difference [23].
When engine torque is higher than 300 N·m, the engine exhaust temperature is higher, in this case, the pinch point temperature difference (PPTD) between engine exhaust and working fluid typically appears at State Point 2 in Figure 3.
ORC systems that use mixed working fluids may have better running performances than pure working fluids [24–25]. The temperature difference between Texh_3 and T2 is the PPTD between the engine exhaust and working fluid.


When engine torque is lower than 300 N·m, the appearance position of the PPTD between engine exhaust and working fluid may change. The change in the mass fraction of components in mixed working fluids can cause changes in the properties of mixed working fluids, such as critical temperature, critical pressure, and slip temperature. Therefore, to eliminate the influence of the appearance position variation of the PPTD, the cases of engine torque being less than 300 N·m are not considered in the following analysis.
The change in the mass fraction of components in mixed working fluids can also affect the running performances of the ORC system.Although some researchers have mentioned the variation law of running performances of the ORC system under various operating conditions of the vehicle engine, few researchers have definitely presented the control strategy of the operating parameters of the ORC system to recover the engine exhaust energy effectively in the whole operating range. As seen, with the increase of engine speed and torque, the net power output of the six kinds of mixed working fluids increases gradually, this is primarily because with the increase of engine speed and torque, the available exhaust energy rate increases (as shown in Figure 1), then more waste heat can be absorbed by the working fluids, and more power output is obtained.When the engine operates under constant operating condition, with the decrease of mass fraction of R152a in the mixed working fluids, the net power output of the ORC system decreases gradually. Generally, zeotropic mixtures are superior to pure fluids in ORC system performance, but although some researchers have considered applying zeotropic mixtures to an ORC system in recovering waste heat from vehicle engines, but we still have a lot of research work to do on selecting suitable zeotropic mixtures for ORC system.The running performances of the IC engine typically vary. As shown in Table 5, with the decrease of mass fraction of R152a in the mixed working fluids, the enthalpy difference between the expander outlet and inlet (namely State Points 3 and 4 in Figure 3) decreases gradually, this is the main reason leading to the decrease of the net power output of the ORC system.
The working conditions of the ORC system must be designed according to the variation of the engine waste heat under various operating conditions. The engine exhaust energy usually fluctuates within a certain range, therefore, the operating parameters of the ORC system should be regulated according to the engine exhaust energy rate, and then the exhaust energy can be recovered effectively. In this study, the test data of diesel engines were measured in the whole operating range of the vehicle.
In this study, we match the ORC system with the vehicle diesel engine by regulating the mass flux rate of the mixed working fluids.Figure 8 shows the MAPs of the mass flux rate of the six kinds of mixed working fluids under engine various operating conditions. The variation law of the engine exhaust energy rate under various operating conditions was studied. With the increase of engine speed and torque, the mass flux rate of the six kinds of mixed working fluids increases gradually, this is primarily dependent on the exhaust energy rate. The improvement in engine thermal efficiency after coupling with an ORC system was also analyzed.
R245fa and R152a were selected as the components of the mixed working fluid, then six kinds of mixed working fluids with different compositions were presented, the effects of mixed working fluids with different compositions on the running performances of the combined system were studied [28]. In this study, an evaluation index called output energy density of working fluid (OEDWF) is proposed to measure the power output of the per unit mass flux rate of working fluid. The control strategy of the operating parameters of the ORC system was introduced, we thought that the mass flux rate of the mixed working fluids should vary with engine operating conditions, namely the mass flux rate of the working fluids should be regulated effectively. We hope that we can provide a useful reference for researchers interested in recovering waste heat from vehicle engine exhaust. With the decrease of mass fraction of R152a in the mixed working fluids, the OEDWF of the working fluid decreases gradually. Diesel Engine ExperimentWe surveyed the experimental data of a six-cylinder four-stroke diesel engine in the whole operating range.
As seen from the table, with the increase of engine power output, the exergy destruction rate of each component increases gradually, therein, the exergy destruction rate of evaporator is much higher than that of pump, expander and condenser. The data mainly includes engine speed, engine torque, power output, fuel consumption rate, intake air flow rate and exhaust temperature. Under identical engine operating conditions, with the decrease of mass fraction of R152a in the mixed working fluids, the exergy destruction rates of pump, evaporator and expander decrease gradually, while the exergy destruction rate of condenser firstly increases, then decreases.
All the values are reserved three decimal points, when the engine power output is low, the exergy destruction rate of the pump all show the same values but should decrease gradually.An indicator called waste heat recovery efficiency (WHRE) is proposed in this study to assess the utilization ratio of the available engine exhaust energy rate.
Table 2 lists the experimental data of the diesel engine under several operating conditions.The variation law of the exhaust energy rate under engine various operating conditions was studied to realize the efficient recovery of the exhaust energy in the whole engine operating range. The contour lines of the WHRE corresponding to the six kinds of mixed working fluids are the same but represent different values.
When the engine power output is higher than 164.5 kW, with the increase of engine speed, the WHREs increase gradually.
When the engine operates under constant operating conditions, with the decrease of mass fraction of R152a in the mixed working fluids, the WHREs decrease gradually, therein, M1 has the maximum value, being 10.90%.
The WHREs are dependent on the available exhaust energy rate and the net power output of the ORC system. From Figure 7, it can be seen that when engine operates under constant operating conditions, with the decrease of mass fraction of R152a in the mixed working fluids, the net power output of the ORC system decreases, while the available exhaust energy rate is constant, then the WHREs decrease gradually.In this study, an evaluation index called engine thermal efficiency increasing ratio (ETEIR) is defined. When engine power output is higher than 132.0 kW, with the increase of engine speed and torque, the ETEIRs increase gradually. This indicates that when the engine operates with high power output, the engine thermal efficiency improvement is better. When the engine operates under constant operating conditions, with the decrease of mass fraction of R152a in the mixed working fluids, ETEIRs decrease gradually, M1 corresponds to the maximum ETEIR, being 11.29%.
The ETEIRs are primarily dependent on engine power output, engine available exhaust energy rate and net power output of the ORC system.The condensing temperature is a key factor that affects the running performances of the ORC system.
Figure 12 shows the variation of the condensing temperatures for the six kinds of mixed working fluids. With the decrease of mass fraction of R152a in the mixed working fluids, the condensing temperature increases gradually.The above analysis reveals that the decrease of the mass fraction of R152a in the mixed working fluids decreases the running performances of the ORC system.
A low condensing temperature benefits the elevation of the running performances of the ORC system. In practical applications, extremely low condensing temperatures cause difficulties in economically providing coolant or a low temperature heat source. Conclusions(1)Thermal efficiency decreases gradually with the decreasing mass fraction of R152a in mixed working fluids. The net power output, OEDWF, WHRE, and ETEIR decrease with the decreasing mass fraction of R152a in the mixed working fluids. Therefore, improved running performances of the combined system can be obtained when the engine operates with high power output.(3)The mass flux rate of the mixed working fluids varies for different engine operating conditions.
Furthermore, the mass flux rate of the working fluids should be effectively regulated to efficiently recover the engine exhaust energy in the whole operating range of the vehicle diesel engine.(4)The running performances of the combined system are better with higher R152a mass fraction.



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