Thursday, February 28, 2013

Textbooksnow.com IS SCAM

BEWARE!!!!!!!!!!!!!
DON'T EVER BUY FROM THIS SELLER:
http://www.amazon.com/shops/textbooksnow-
or Textbooksnow.com

YOU WILL GET SCAM
I bought the text book: 
International Politics (11th Edition) by Robert J. Art and Robert Jervis
from textbooksnow-
on January 11th, 2013
They said the package will arrive between 20th Jan - 4th Feb.
Now it is Feb 12th and I haven't received my item yet
The tracking number they give me don't even work, when trying to track the package it will said invalid number, and when you try contacting them they will never reply you back.
I sent them hundreds of email but no reply.

If you file a claim through Amazon it won't help because they will tell Amazon that they already sent it and they will accuse you of lying, then you will lose your money like me.

I just realized that they sell all kind of textbook but it all just a scam, I was complaining to my classmate and friends about this but they told me their stories too, one of my friends bought a book from textbooksnow- and the book she get was in another edition instead of the one listed, my other friends got a publisher review edition book with no index and the back cover, and they never told him about it when he file a claim they just said it is "used condition" and that how "used condition" is. WHAT THEY TELL YOU IS NOT TRUE-they are scammer, all their book description is fake.

DON'T EVER BUY ANYTHING FROM THEM, i know they will have other name and alias but i will try to do more research about them and find out more info.
If you don't believe me then just try for yourself and you will know!!!!!!

==============================================================
UPDATE!!!!!
march 01, 2013

Today I finally received the email message from them:





From:textbooksnow- - Amazon Marketplace (5k6z6xt8t6hfq3w@marketplace.amazon.com)
Sent:Friday, March 01, 2013 1:41:31 AM
To: ------@hotmail.com)
Due to a recent move with our warehouse,
 orders may be shipped, however tracking information
 may not be available.
 We do expect that your order will arrive within
 the guidelines as stated on the Marketplace website 
where your order was placed.

We are unable to cancel any orders at this time. 
If your order arrives late and you no longer need the book(s),
 simply refuse delivery and we will issue a refund 
within 2 business days of receipt. 
On behalf of Textbooksnow.com, 
we sincerely apologize for any inconveniences this has caused.
 Thanks for your continued patience.

90zdysb693yw84c
Textbooksnow.com

-------- Original Message --------
From: <[e-mail address removed]>
Sent: Wed, 13 Feb 2013 20:58:26 +0000
To: [e-mail address removed]
Subject: Order delivery inquiry from Amazon customer

I haven't received the product. 
I have ordered it for more than a month. 
I need it for a class, and now I'm about 
to take my test not too long from now. 
So, if the product is not here anytime soon, 
I would like my money back. So, I can buy a 
new one somewhere else. 




------------- End message -------------

For Your Information: To help arbitrate disputes and 
preserve trust and safety, 
we retain all messages buyers and sellers send through 
Amazon.com for two years. 
 This includes your response to the message above. 
 Amazon.com uses filtering technology t
o protect buyers and sellers from possible fraud. 
Messages that fail this filtering will not be transmitted.

We want you to buy with confidence anytime you purchase
 products on Amazon.com. 
Learn more about Safe Online Shopping 
(http://www.amazon.com/gp/help/customer/display.html?nodeId=10412241)
 and our safe buying guarantee 
(http://www.amazon.com/gp/help/customer/display.html?nodeId=537868).



[commMgrTok:A3MD4P4SKYV6D3]



WHAT A SCAM!!!!!!
THEY SAID :
" simply refuse delivery 
and we will issue a refund within 2 business days of receipt."
 
THEY MUST BE A GENIUS BECAUSE I DID NOT GET THE BOOK!!!! SO HOW CAN I SIMPLY REFUSE THE ORDER???????

I still not sure what to do next I think I will go talk to my bank about this, but I have been really busy and I have many midterm exam right now,
If I have time I will try to find out if they sell on ebay or any other website, as you can see their website: textbooksnow.com is a scam and I can't get any information about them from their website.
I will update again if I see them selling on ebay or any other website beside Amazon




Saturday, February 23, 2013

True or False: The power dissipated by an ideal current source depends only on its output current.



True or False:
The power dissipated by an ideal current source depends only on its output current.

FALSE
it also depends on the voltage



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Get Algebra Help

True or False: To increase the power delivered to a circuit, it is a common practice to use a number of independent voltage sources in parallel.

FALSE
normally voltage source are not put in parallel




Friday, February 22, 2013

True or False: It is impossible to find the equivalent resistance of a non-planar resistor network.

FALSE

Equivalent resistance can be found in any resistor network.

Thursday, February 21, 2013

True or False: For a set of resistors in parallel, the one with the largest resistance will get the largest share of the total current.

FALSE
The one with largest resistance get the smallest share of current.

Wednesday, February 20, 2013

True or False: 1 Watt = 1 Coulomb-Volt/second

TRUE

Reason:
Power(watt) = [current(Coulomb/second)] multiply with [voltage (volt)]

KEY TERM: Joseph Pulitzer



Joseph Pulitzer

Early 1900s newspaper publisher; used “yellow journalism” to stir up public sentiment in favor of the Spanish-American War

KEY TERM: George Dewey



George Dewey
Officer in the United States Navy, 1861-1917; led a surprise attack in the Philippines during the Spanish-American War that destroyed the entire Spanish fleet




KEY TERM: Alfred T. Mahan



Alfred T. Mahan
Author who argued in 1890 that the economic future of the United States, 1809-1817; called the Father of the Constitution for his leadership at the Constitution Convention









KEY TERM: William Randolph Hearst


KEY TERM: William Randolph Hearst


Newspaper publisher from 1887 until his death in 1951; used “yellow journalism” in the 1890s to stir up sentiment in favor of the Spanish-American War






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Friday, February 15, 2013

LECTURE NOTE: Introduction to Organic Molecules and Functional Group



CH3: Introduction to Organic Molecules and Functional Group
-        Functional Group
o   Heteroatoms—atoms other than carbon or hydrogen. Common heteroatoms are nitrogen, oxygen, sulfur, phosphorous, and the halogens
o   Π Bonds. The most common Π bonds occur in C—C and C—O double bonds
o   Functional group is an atom or a group of atoms with characteristic chemical and physical properties. It is the reactive part of the molecule
o   Why do heteroatoms and Π bonds confer reactivity on a particular molecule?
§  Heteroatoms have lone pairs and create electron-deficient sites on carbon
§  Π bonds are easily broken in chemical reactions. A Π bond makes a molecule a base and a nucleophile (donate electrons)
o   C—C and C—H σ bonds form the carbon backbone or skeleton to which the functional groups are bonded (R). R—Functional Group
o   Ethane has only C—C and C—H σ bonds, so it has no functional group. Ethane has non polar bonds, no lone pairs, and no Π bonds, so it has no reactive sites (alkane)
o   Ethanol has two carbons and five hydrogens in its carbon backbone, as well as an OH group (hydroxyl functional group). Ethanol has lone pairs and polar bond that make it reactive with a variety of reagents, including acids and bases (Alcohol)
-        An Overview of Functional Groups
o   We can subdivide the most common functional groups into 3 types
§  Hydrocarbons
§  Compounds containing a C—Z σ bond where Z = an electronegative elements
§  Compounds containing a C=O group
o   Hydrocarbons are compounds made up of only the elements carbon and hydrogen. They maybe aliphatic or aromatic
§  Aliphatic hydrocarbons can be divided into three subgroups
·        Alkanes have only C—C σ bonds and no functional group. Ex. Ethane (CH3CH3)
·        Alkenes have a C—C double bond as a functional group. Ex. Ethylene (CH2=CH2)
·        Alkynes have a C—C triple bond as a functional group. Ex. Acetylene (HC triple bond CH)
§  Aromatic hydrocarbons (named after the strong and characteristic odors). Ex. Benzene, the sixed membered ring and three Π bonds of benzene comprise a single functional group
·        When benzene is bonded to another group, it is called phenyl group (phenylcyclohexane)
§  Polyethylene is a synthetic plastic and high molecular weight alkane, consisting of chains of CH2 groups bonded together (no reactive site, so stable compound and not readily degrade)
o   Compound containing C—Z σ bond. The electronegative heteroatom Z creates a polar bond, making carbon electron deficient. (lone pairs on Z are available for reaction with protons and other electrophiles, especially Z=N or O)
§  Halo group (R—X) X= F, Cl, Br, I
§  Hydroxyl group (R—OH)
§  Alkoxy group (R—O—R)
§  Amino group (R—NH2, R2NH, or R3N)
§  Mercapto group (R—SH)
§  Alkylthio group (R—S—R)
o   Compounds containing a C=O group (carbonyl group)
§  The polar C—O bond makes the carbonyl carbon an electrophile, while the lone pairs on O allow it to react as a nucleophile and base. The carbonyl group also contains a pie bond that is more easily broken than a C—Z σ bond
§  Atenolol is a βblocker, a group of drugs used to treat hypertension
§  Carbonyl group (R—(CH=O)) or (R—(CR=O))
§  Carboxy group (R—(C(OH)=O))
§  COOR (R—(C(OR)=O))
§  CONH2, CONHR or CONR2
§  COCl (R—(CCl=O))
o   The importance of a functional group cannot be overstated. A functional group determines all the following properties of a molecule:
§  Bonding and shape
§  Type and strength of intermolecular forces
§  Physical properties
§  Nomenclature
§  Chemical reactivity
-        Intermolecular forces – are the interactions that exist between molecules. Functional group determines the type and strength of these interactions
o   Ionic compound (extremely strong electrostatic interactions)
o   Covalent compounds (in order of increasing strength)
§  Van der Waals forces (London forces)
·        Caused by momentary changes in electron density in a molecule (the only attractive forces present in nonpolar compound)
·        When compound is not completely symmetrical, creating temporary dipole
·        The weak interaction of these temporary dipoles constitutes van der Waals forces
·        The larger the surface area, the larger the attractive force between two molecules, and the stronger the intermolecular forces
·        Polarizability is a measure of how the electron cloud around an atom responds to changes in its electronic environment
·        Larger atoms like iodine, which have more loosely held valence electrons, are more polarizable than smaller atoms like fluorine, which have more tightly held electrons.
o   More loosely, so easily induced by temporary dipoles
§  Dipole-dipole interactions – are the attractive forces between the permanent dipoles of two polar molecules
§  Hydrogen bonding – typically occurs when a hydrogen atom bonded to O, N, or F, is electro statistically attracted to a lone pair of electrons on an O, N, or F atom in another molecule
-        Physical Properties (Compound’s intermolecular forces determines many of its physical properties)
o   Boiling point (bp) – is the temperature at which a liquid is converted to gas
§  Stronger the intermolecular forces, the higher the boiling point
·        Ionic compounds have very high boiling points
·        Covalent molecules, the boiling point depends on the identity of the functional group
·        The larger the surface area, the higher the boiling point
·        The more polarizable the atoms, the higher the boiling point
·        Liquid having different boiling point can be separated in the laboratory using a distillation apparatus
o   The more volatile component (lower boiling point compound) distills first, followed by the less volatile, higher component
o   Melting point (mp) – is the temperature at which a solid is converted to its liquid phase
§  The stronger the intermolecular forces, the higher the melting point
§  Given the same functional group, the more symmetrical the compound, the higher the melting point
·        Ionic compounds have very high melting points
§  Symmetry also plays a role in determining the melting points of compounds having the same functional group and similar molecular weight, but very different shapes
o   Solubility – is the extent to which compound, called the solute, dissolves in a liquid called the solvent
§  Compounds dissolve in solvents having similar kinds of intermolecular forces
·        “Like dissolves like” (structurally similar)
·        Polar compounds dissolve in polar solvents. Nonpolar or weakly polar compounds dissolve in nonpolar or weakly polar solvent
§  Water and organic liquids are two different kinds of solvents (water is polar, organic solvents are either nonpolar or weakly polar
§  Most ionic compounds are soluble in water, but insoluble in organic solvents. To dissolve an ionic compound, the strong ion-ion interactions must be replaced by many weaker ion-dipole interactions
§  An organic compound is water soluble only if it contains one polar functional group capable of hydrogen bonding with the solvent for every five C atoms it contains
§  Acetone is so soluble in water that acetone and water are miscible—they form solutions in all proportions with each other
§  A low molecular weight alcohol like ethanol is water soluble because it has small carbon skeleton (< five C atoms) compared to the size of its polar OH group
·        Cholesterol is insoluble in water
§  The nonpolar part of a molecule that is not attracted to H2O is said to be hydrophobic
§  The polar part of a molecule that can hydrogen bond to H2O is said to be hydrophilic
§  MTBE soluble in water, 4’-dichlorobiphenyl is not soluble in water, but in organic solvent
-        Application: Vitamins
o   Vitamins are organic compounds needed in small amounts for normal cell function (A, C, D, E,K) (B1, B2, B12)
§  Vitamin A or retinol is an essential component of the vision receptors in the eyes (mucus membrane and skin)
§  Contains 20 carbons and a single OH group, making it water insoluble (soluble in any organic medium (stored in fat cells, particularly in liver)
§  Beta carotene, the orange pigment (carrots)
o   Vitamin C
§  Has six carbon atoms, each bonded to an oxygen atom that is capable of hydrogen bonding, making it water soluble
-        Application of solubility: Soap
o   Soap molecules have two distinct parts:
§  Hydrophilic portion composed of ions called polar head
§  A hydrophobic carbon chain of nonpolar C—C and C—H bonds, called nonpolar tail
§  Dissolving soap in water forms micelles, spherical droplets having the ionic heads on the surface and the nonpolar tails packed together in the interior
-        Application: The Cell Membrane
o   Structure of the cell membrane
§  The cytoplasm is the aqueous medium inside the cell, separated from water outside the cell by cell membrane
§  Phospholipids, contains a hydrophilic ion portion and hydrophobic hydrocarbon portion, in this case two long carbon chains composed on C—C and C—H bonds (a polar head and 2 nonpolar tails)
§  When phospholipids are mixed with water, they assemble in an arrangement called lipid bilayer, with the ionic heads oriented on the outside and the nonpolar tails on the inside
§  Cell membranes are composed of these lipid bilayers
o   Transport across cell membrane
§  Some ions are transported across the membrane with the help of molecules called ionophores
·        Ionophores are organic molecules that complex cations. They have hydrophobic exterior that makes them soluble in nonpolar interior of the cell membrane, and a central cavity with several atoms whose lone pairs complex with a given atom (central cavity to hold cation)
·        Two naturally occurring antibiotics that act as ionophores are
o   Nonactin
o   Valinomycin
·        Several synthetic ionophores have also been prepaed, including one group called crown ethers ( are cyclic ethers containing several oxygen atoms that bind specific cations depending on the size of their cavity)
o   Functional Group and Reactivity
§  Functional group create reactive sites in molecules
§  Electron-rich sites react with electron-poor site
§  All functional groups contain a heteroatom, a pie bond, or both, and these features make electron-deficient (electrophilic) and electron rich (nucleophilic) sites in a molecule
§  An electronegative heteroatom like N, O, or X makes a carbon atom electrophilic
§  A lone pair on a heteroatom makes it basic ad nucleophilic
§  Pie bonds create nucleophilic sites and are more easily broken than sigma bonds
§  An electron-deficient carbon atom reacts with nucleophile, symbolized as :Nu-
§  An electron-rich carbon reacts with an electrophile, symbolized as E+
-        Biomolecules – are organic compounds found in biological systems
o   Sugar, amino acids, lipids and nucleotides



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