Discussing The Development Of People’s Lives Writing Sample

My fifth course at Pacific Oaks was Social and Political Context of Human Development. After taking this course, I had better understand about varieties socials identifiers of race, sexual orientation, class, gender, and ability. I also recognized many attitudes towards those social issues that are known as one of the main factors impact on our everyday lives. In addition, I had chances to share my thoughts, and listen to my classmate’s stories at the check-in. I also had opportunities to work in the small group discussion that helped me to understand more diverse cultures and backgrounds. The weekly writing assisted me to get better at express my thoughts in English.

I have learned new information about how children learn was children enrich their knowledge from people around them, and living environment has a great impact on the children’s development. For example, children get negative stereotypes from their families and people around them. However, those negative stereotypes or assumptions that people make them, but they have a great impact on people’s lives. In this class, I also noticed living environment is one of the key elements that impact on the children’s development. For example, children, who are from poor families, are more likely to have low self-esteem. Their lives are very stressful when they see their parent is working hard, but they don’t earn enough for their basic needs such as home, food, and health.

This class added to my knowledge of working with children because I experienced with how to identify social portraits. Personally, I think that understanding children’s social identities portraits will help me to know their background and search information relates to their differences. In addition, this class enriched my knowledge about the impact of social issues on people’s lives, especially children’s development that will assist me to help and support children to express their thoughts and success at school. I also share resources to help their family. For example, currently I am working in Early Head Start toddler classroom for low-income families, so this class gained my knowledge about different struggles around them.

Recognize their difficulty in diverse families’ lives, I will be there to support them whenever they need information to assist them to break the cycle of poverty. My aha moment was the field trip, Unity, and Pride Rally at the Plaza de Cesar Chavez because I had chances to meet LGBT communities and listen to their presentations on struggles they are facing in their lives. Their stories touched my heart, so I remind myself of introducing LGBT communities to diverse families as well as children by providing books, and pictures relating to LGBT because they are deserved to be respected and treated equality.

Discussion Abrasive Electrochemical Grinding

According to B. Mallick at el conducted an experimental investigation for machining by micro-ECDM, each variable was coded and the upper level was taken as +1 and the lower level as – 1 of every process parameter in order to design the experiments in an optimized way. Flat end cylindrical stainless tool of diameter 250µm were used for each experiment and the experiments were conducted in a NaOH solution. The process parameters i.e. voltage, electrolyte concentration, duty ratio and pulse frequency was varied. Through this experiment it was found that the MRR increases when the applied voltage, electrolyte concentration, duty ratio is increased and decreases. Overcut always increases with increase of applied voltage, electrolyte concentration, duty ratio but it decreases with increase of pulse frequency up to 600Hz after that it will increase.

According to Sanjay K. Chak among these methods such as, abrasive electric discharge grinding (AEDG), abrasive electro chemical grinding (AECG), abrasive electric discharge machining (AEDM) / powder mixed electric discharge machining (PMEDM),) Abrasive assisted electrical machining, ultrasonic assisted electrical discharge machining (USEDM). Abrasives assisted ECDM process is gaining more popularity especially in micro machining of electrically non-conductive materials, because it involves combined action of electrical discharge, chemical etching and abrasive cutting. In this method it is found that Smaller abrasive grit size improves the dimensional accuracy and surface finish of the product that diametric overcut and surface roughness increased with increase in grit size. Material removal rate also increased with increase in abrasive concentration.

According to A. Kulkarni at el the ECDM cell has been fabricated using a Boro- silicate glass flask of 10 cm diameter. The arrangement of cathode, anode, and workpiece. The separation between the cathode tip and the workpiece was of the order of 400–500 µm. The depth of cathode inside the electrolyte was also maintained at a fixed distance where one gets the spark. The distance between cathode and anode is kept fixed at 3 cm in all the experiments. This experiment shows that the electrons flows towards the workpiece kept near the cathode tip. This flow of electron is seen as a current spike of about 20 A or more for a short duration of a few milliseconds the bombardment of electrons it raises the temperature of the workpiece briefly and then the temperature decreases due to quenching.

According to Amitabha Ghosh Electro Chemical Discharge machining has eliminate the limitation possessed by the ECM or EDM. This paper also states that though it appears to have potential for machining electrically non-conductive materials, it also has very limited acceptance because of its limited acceptance. A number of experiments had been conducted on this paper where the ECDM using artificially introduced inductance in the circuit (Basak 1991; Basak Ghosh 1995b) and it has been seen that increasing the inductance in the circuit increases the material removal rate. Another manufacturing application of ECDM is micro welding and it also possess great potential in fused deposition modeling for rapid prototyping.

According to Anjali V. Kulkarni in t5thisn paper the author states that ECDM is the hybrid machining process which comprises of techniques of Electro Discharge Machining (EDM) and Electro Chemical Machining (ECM). It is also known as electro chemical spark machining (ECSM) process. In this experiment anode was made up of inert materials while cathode is normally made of copper, dilute hydrochloric acid (HCl) was used as the electrolyte, a pyrometer was used to sense the high transient temperature. The experiment was also performed on silicon, brass and tantalum as work piece material. Through this experiment it was found that for the first time the transient and co-exist measurements were found. It was also found that the rise in the temperature was because of the bombard of electrons during the discharge process and that it can also be used for micro fabrication.

According to Yong Liu at el, conducted and experiment of ECDM with a rotary helical electrode to fabricate ultra-clear glass. Using a rotary helical tool in electrochemical discharge drilling, electrochemical discharge milling, and wire ECDM, the effects of pulse voltage, frequency, duty factor, and feed rate on the used were pulse voltage—37 V, frequency—3000 Hz, duty factor—70%, feed rate—1 _m/s, spindle speed—3000 rpm, and electrolyte—3 mol/L KOH.

It was found that high quality array micro holes were successfully fabricated with a lower diameter, Thickness of the glass was300 _m. A minimum side gap of 27.2_m could be obtained with electrochemical discharge drilling. This paper also established a mathematical model for ECDM process to guide the machining of microstructures on ultra-clear glass, and with the increase in voltage the side gap also increases.

According to Indrajit Basak at el, in this paper the author compares the ECDM and Electro Chemical Arc Machining (ECAM) and the work piece due to the breakdown of the entrapped bubbles, which phenomenon has been confirmed through a number of experiments. On the other hand, in ECDM the discharge is between the tool and the surrounding electrolyte. the electrodes is in the range of 280-300 V, while in ECDM discharge occurs when the value of the applied voltage is in thes range of 20-40 V. The author set up an experiment for material removal rate through ECDM, and it was found that A variable full-wave rectified D.C. supply of frequency 100 Hz was provided by means of a variac and a rectifier.

Experiment Factors Of Dissolved Oxygen

In this experiment factors of dissolved oxygen as well as depth were manipulated to examine their effects on both opercula beats per minute as well as breaths taken by the test specimen Corydoras aeneus per hour. The oxygen concentration was decreased by bubbled nitrogen gas through the water until it became more abundant that the oxygen gas. The initial dissolved oxygen concentration was found to be 5.74 mg/L, where the opercula beats/minute was calculated to be 163 beats/minute.

The dissolved oxygen concentration was then manipulated to concentrations of 4.46mg/L, 3.98mg/L, 2.61mg/L and lastly, 1.70mg/L, whereby the opercula beats showed a steady increase going from 163 beats/minute to 193 beats/minute. The test specimen only took 20 breaths/hour at the dissolved oxygen concentration of 1.70mg/L. The steady increase of opercula beats per minute, suggests that the catfish increases its ventilation to extraction as much oxygen as it can in the decreasing oxygen water. Therefore, as dissolved oxygen decrease, ventilation increases, quicker aquatic respiration extracts more oxygen for the fish’s bodily needs. Notably, at 1.73mg/L the fish was able to take 20 breaths/hour at the water’s surface and this is solely due to the fact that the water has become so deprived of dissolved oxygen that the Corydoras aeneus then utilized aerial respiration. Thus, it’s at 1.73mg/L where the catfish switches from aquatic respiration to aerial respiration.

With respect to increasing depth and its effect on opercula beats/minute, there was a steady increase of opercula beats/minute from 249 beats/minute at 8cm to 273 beats/minute at 25cm. Even though the test specimen was in low oxygenated water, it’s ventilation was quickened, as to extraction as much oxygen as possible. Though, theoretically, it would’ve been more energetically efficient to utilize aerial respiration, in this case there is a trade-off with the energy consumed to actually swim to the surface and utilize aerial respiration versus conserving as much energy as possible and even decreasing ventilation. Essentially, it becomes more energetically efficient for the catfish to remain at the bottom and converse its energy, rather than expending that same energy to swim to the surface to utilize aerial respiration and swim back to the bottom. Additionally, staying at the bottom helps to avoid predators. The graph shows initial increase and a decrease, this pattern continued, and this maybe the catfish’s method of first extracting as much dissolved oxygen, and trying to decrease ventilation to converse energy and then again increasing ventilation to extract as much dissolved oxygen, thus continuing the pattern.

Aerial respiration has quite a few advantages and some disadvantages over aquatic respiration. Physiological advantages of utilizing aerial respiration over aquatic respiration is that air contains at least 30 times more oxygen per unit volume than water, but this varies due the effect of temperature. Additionally, air is less dense than water by 100 times and 30 times less viscous than water. Thus, air as a respiratory medium is physically easier to extract oxygen whilst passing it over a respiratory surface, such as lungs or gills, thus being energetically less cost. Ideally, a fish of 100 g naturally has to move approximately 30 to 65 g of water per minute through its gills; that is 1/3 to 2/3 of its body weight, consequently making it a physically exhausting process (Reebs 2007). Aquatic respiration has disadvantages such that the oxygen content in water is much lower than that of air. Additionally, the rate of diffusion is greatly slower, however, aquatic organisms benefit since their respiratory surfaces are always kept moist and gives them their natural buoyance as their plasma and water density is approximately equal. Fishes that live in commonly hypoxic habitats may have more haemoglobin in their red blood cells, and more of those cells in their blood, and therefore a higher blood capacity to take up and transport oxygen (Reebs 2007). Corydoras aeneus possess several adaptations that make it ideal for aerial respiration even though being an aquatic organism.

This catfish posterior intestine is modified so that it can function as an air breathing organ by being air filled, thin-walled and highly vascularized. This area is the longest region in the gut (Persaud, Ramnarine and Agard 2000). Aerial respiration happens in a rapid dash to the surface, taking in air during the 0.06-0.07s that the mouth is exposed and expiration occurs via the anus while going back down (Kramer and McClure 1984-1991 ).

Fish increase their efficiency in oxygen uptake in several ways but mainly through their gills, which are located one set on either side of the body and near the back of the head they are open to the gullet at the front, and open to the external environment behind. Thus, water can flow constantly through the mouth and passing through the gills. Some gills especially in bony fish have a plate, an operculum protecting and regulating the opening and closing of the gill. This ability to have water continually passing over the gills is one of the major factors making gills more efficient than lungs. With lungs the air comes in, fills the space, and then must be expelled before any more oxygen rich air can be brought in.

Since the gills are open, no energy is spent on expelling old air or reversing direction of flow. Gills have numerous folds that give them very large surface area. The rows of gill filaments have many protrusions called gill lamellae. The folds are kept supported and moist by the water that is repeatedly pumped through the mouth and over the gills. These lamellae have an efficient transport system that maintains the concentration gradient across the lamellae. As water is flowing past the gills in the opposite direction referred to as counter current flow. In counter current flow blood low in oxygen passing through the lamella comes into close contact with water that is fully saturated with oxygen, thus a concentration gradient is formed. The oxygen from the water diffuses into the blood moving along the lamella, this continues until both water and blood are saturated, eliminating the gradient. However, since blood flows in the opposite direction it always flows next to water high in oxygen, thus the blood can absorb as much oxygen as possible. In comparison to mammals that lose their gradients over distances, counter current flow always has a sustained gradient.